The plot of Wonder Boy in Monster Land follows the events in its predecessor, Wonder Boy. The game's main protagonist is a young boy named Bock Lee Temjin, in which his friends call him "Tom-Tom". In Wonder Boy Tom-Tom's girlfriend Tanya was kidnapped by the "evil King" and was taken to his woodland kingdom; Tom-Tom set out to the kingdom, defeated the evil King, and saved Tanya. Word spread throughout Wonder Land about Tom-Tom's quest, and people bestowed upon him the title of "Wonder Boy".

Following the evil King's defeat, peace reigned over Wonder Land for eleven years. Then, one day, a fire-breathing dragon called the "MEKA dragon" appeared and terrorized the land. The people, helpless and not skilled in fighting, were defeated by him and his minions; they quickly took over the land, and Wonder Land became known as "Monster Land". The people send out for Wonder Boy, now a teenager, as Wonder Land's only chance to defeat the monsters and demons who inhabited the land and to defeat the MEKA dragon. The disposed Mayor gives Wonder Boy a sword and a life potion and sets him on his way.

Wonder Boy in Monster Land was created by Ryuchi Nishizawa and Michishisto Ishizuka, two of the three members of a newly found company called Escape. After the release of the first Wonder Boy game, they rebranded the company as "Westone" – as the first letter in Nishizawa's name means "west", while the first on Ishizuka's name means "stone". Nishizawa, originally an arcade game developer, was trying to take advantage of the quickly emerging role-playing video game genre, with games such as The Black Onyx, Wizardry, and Dragon Quest. He tried to create a game that fused together arcade and RPG elements. The jungle backdrop was overhauled and replaced with a medieval one with castles and caves. As with RPGs, he intended for the player to start with no items or strength, and for players to buy items, spells, health, and better equipment. Later in the game's development, Shinichi Sakamoto came on board to compose its soundtrack; in an overview of the series by IGN, they said that the music "was a sigh of relief for those still haunted by the repetitive loops of the arcade original", adding that it contributed to the RPG style and that would establish the standard for all future Wonder Boy games in the series.

The game would be published by Sega in 1987 and released for the arcade. It ran on a Sega System 2 board. It was based on a Z80 processor that runs at 4 MHz, with audio provided by two SN76489 (also known as SN76496) chips that run at 4 MHz each. It used raster standard graphics and monaural sound. Upon its release for the arcades in Japan in 1987, Wonder Boy: Monster Land had slow sales, but it would eventually pick up to become a decent seller. Sega ported the game to its Master System console in 1988, where in Japan it was titled Super Wonder Boy: Monster World. It was also ported by Activision for the Amiga, Atari ST, Commodore 64, Amstrad CPC, and ZX Spectrum in 1989. The Activision-published version bore the title of Super Wonder Boy in Monster Land on their packaging artwork.Hudson Soft released a version of the game titled Super Adventure Island for mobile phones on June 8, 2005 (2005-06-08). The Master System version was released for the Wii's Virtual Console service in Japan on December 14, 2008 (2008-12-14), in Europe on January 23, 2009 (2009-01-23), and in North America on January 26, 2009 (2009-01-26). Sega release the arcade version for the Virtual Console, PlayStation Network, Xbox Live Arcade – along with The Revenge of Shinobi, Alex Kidd in Miracle World, the Arcade port of Super Hang-On, Monster World IV, and Wonder Boy in Monster World – as part of its third Sega Vintage Collection package in May 2012.

Wonder Boy in Monster Land has been cloned, hacked and re-marketed a number of times over the years with varying degrees of legality. Jaleco released a modified port of the game to the Family Computer, changing the graphics and character sprites so that it resembled the Chinese novel Journey to the West. They titled the game Saiyūki World, changed its protagonist to Sun Wukong, and changed the setting to Ancient China; they released the game on November 11, 1988 (1988-11-11). This game would have a sequel called Saiyūki World 2 in Japan and Whomp 'Em in North America. Similarly, Hudson Soft ported a version of Wonder Boy: Monster Land titled Bikkuriman World, where they changed the graphics and characters to those from the Bikkuriman anime franchise. They released the game for the PC Engine on October 30, 1987 (1987-10-30).Tectoy, Sega's distributor in Brazil, used the game's license and code to produce Mônica no Castelo do Dragão for the Sega Master System in 1989. Here, the characters were replaced with known figures from the Brazilian comic book series Monica's Gang (Turma da Mônica), and Monica was re-cast as the game's main character. The game is considered the only legal remake of any game in the Wonder Boy series.

Reception
Publication	Score
	Amiga	C64	Atari ST	ZX Spectrum	Master System
Amiga Joker	73%
Amiga User International	65%
Amiga Action	52%
Amiga Format	51%
CU Amiga	41%
Zzap!64	36%	68%
Power Play	80%
The Games Machine		71%	88%
Datormagazin		8/10
Zero			85%
Génération			88%
CRASH				88%
Your Sinclair				75%
Sinclair User				90%
MicroHobby				42/60
Computer and Video Games					9/10
Dragon
Allgame
IGN					7.5/10

The Sega Master System version of the game was reviewed in the June 1988 issue of Computer and Video Games, which gave it an overall score of 9 out of 10. It described the game as a "total mix of arcade, strategy and adventure" with "role playing elements" such as "interaction with other characters and the ability to develop your character." It further stated that the "graphics rate as some of the best seen to date on a Sega game" and the "playability is supreme," concluding that it pushes its game design "to new horizons, all of which makes for longterm playability and interest." It was also reviewed in the April 1989 issue of Dragon by Hartley, Patricia, and Kirk Lesser in "The Role of Computers" column. The reviewers called it "a good game with a bad name", considered the game play superb, and concluded that the game "is one of SEGA's classic products." They stated that the arcade, strategy and role-playing action elements combine to make it "a truly original and enjoyable game" and that Sega has "done an excellent job" overall, giving the game 4½ out of 5 stars.Allgame also gave the game 4½ out of 5 stars, with reviewer Jonathan Sutyak describing it as "one of the best games I have ever played on the Master System."IGN in 2009 described the Virtual Console release as an "interesting platformer/RPG hybrid" game.

The ZX Spectrum version of Wonder Boy in Monster Land received preview coverage in Your Sinclair magazine. They praised the new additions made to the game that separated it from Wonder Boy; they called the game "a good arcade adventure with a smattering of strategy thrown in". The magazine reviewed the game four months later. The reviewer noted the diverse level designs and many "surprises" the player will encounter, and they praised the game's learning curve, saying that it "is well thought out and you really feel as if you made some progress before you die". It was criticized for its long multi-load times on the ZX Spectrum, its jumping mechanics in which the character "floats around", and the graphics which was not as good as its predecessor. The reviewer called Wonder Boy in Monster Land "a souped-up version of Wonderboy, which improves much on the original theory but at a slight cost to gameplay". Reviewers from UK-based magazine The Games Machine called it "probably the best conversion you could expect on the Spectrum".

CRASH magazine praised the ZX Spectrum version of the game for its detailed sprites and smooth movements, playability, and combat system. The reviewer further commended the game for the differences that set it apart from the original Wonder Boy game, citing the cartoon-like feel and the vast arrays of enemies and items; just as in Your Sinclair, it was criticized for its slow multi-loading. Overall, the reviewer said the game is "great fun for the experienced games player or the person just starting out in the Spectrum world".Sinclair User magazine praised its gameplay, citing the ability to stab enemies with a sword, to collect gold and items left behind, and to go into shops and pubs and buy equipment. Further praise went to the colorful and detailed graphics and animations, though they said they tend not to perform well in more complex background settings. Spanish magazine MicroHobby said that the ZX Spectrum version brought nothing new from its arcade counterpart, but the execution was good; they lauded the game's graphics and its challenging and addictive gameplay, but they criticized it for its lack of originality.

The Commodore 64 and Atari ST versions of Wonder Boy in Monster Land also received similar praise from gaming magazines. The Games Machine praised the Atari ST version but criticized the Commodore 64 version. The reviewers said the former "is not only playable, but the graphics are the nearest to the arcade machine you're going to get"; however, they said the graphics in the latter, while colorful, were too block-like and ruined its overall presentation. Reviewers from Zzap!64 criticized the Commodore 64 version, saying that this version is only slightly better and more playable than the Amiga version. Moreover, they said this version also suffered from repetitive gameplay and "inefficient multi-load", though an improvement from the Amiga version.Zero gave a fair assessment of the Atari ST version, appreciating the "cutesy" and cartoon-like graphics and addicting gameplay, which the reviewer said is "very easy to get into and very hard to put down"; they criticized the game's lack of any save features, saying that some of the gameplay gets repetitive after a while. Swedish magazine Datormagazin acclaimed the Commodore 64 version in most aspects. They lauded its graphics for being simplistic but clean, but they noted that they were not sensational. They criticized the game for its music, which they said can become annoying after a while, and for its lack of save points. Overall, they gave a positive review, saying that it "is a perfect example of how to make a game that is fairly simple to play but still is fairly advanced".

The Amiga version of Wonder Boy in Monster Land received mixed responses, but most reviews were negative. CU Amiga magazine expressed disappointment over the major change in the gameplay and the protagonist himself from the game's predecessor. The review also criticized sharply the game's poor graphics and character sprites, saying that "many of the characters are short and stumpy", that the background resembles that of Boulder Dash, and that Wonder Boy "is as wide as he is tall". Other criticisms included substandard screen scrolling, terrible gameplay due to the game's slowness, and that the actual gameplay area has been drastically reduced in size to include gameplay statistics such as the life meter and score displays.IGN heavily criticized the Amiga version 20 years after its release, saying how Wonder Boy was depicted as "a diaper-clad baby".

Amiga Format similarly gave the game poor ratings, including the small gameplay area as a result of displaying the other statistics, sound that is substandard to the Amiga computer's expectations, the lack of a "high score" feature, and limited continues (as opposed to the arcade version which had unlimited continues). The reviewer said that "the game hasn't been programmed to make use of any of the Amiga's features" and that it "is another in the sadly increasing number of games that has simply been ported over from the first conversion, so that none of the features that make Amiga games stand out are included".Zzap!64 complained about the version's "beepy" sound and the very slow multi-load times, saying that the player may spend more time waiting for the game to load levels than play it. It also noted the lack of detail and variety in the graphics which did not make up for the slow multi-load times; the reviewer said that the enemies looked "about as dangerous as a dead tortoise".

Other reviews from computer magazines gave the Amiga version of the game more positive reviews. Amiga User International praised the game's graphics, which they said were translated from the arcade version near-perfectly. It also appreciated the game's cartoon-style graphics, which said befits the game well. However, the review noticed that the game's code came from the Atari ST version, which, as noted in the other reviews, has resulted in choppy scrolling and a shrunken gameplay area – something which "the Amiga could do all this perfectly smoothly with one hand tied behind its back". The review also criticized its slow multi-load times and high retail price. German magazine Amiga Joker liked the game's "candy-like graphics" and gameplay style, which they said compared to the unreleased title The Great Giana Sisters. However, the reviewers criticized it for its choppy scrolling and sound, of which they said "David Whittaker has already produced much better sound".

Wonder Boy in Monster Land received additional coverage years after its release. A 2004 review from Honest Gamers highly lauded its gameplay, challenge, and sound. It noted that while the game starts easy, the difficulty increases at a decent rate and involves good general gameplay skills that serve to add to the gameplay value. The reviewer praised the sound for being simple yet very effective, saying that it "is the ultimate compliment to pay a video game score" and comparing it to other Sega Master System titles such as Alex Kidd. A 2008 IGN feature listed the game as one of "The 7 Master System Games You Need"; the reviewer said the game "is one of the finest adventures in a long series of [Wonder Boy] games", praising its brightly colored graphics and character sprites, and its sound. IGN had its sequel, Wonder Boy III: The Dragon's Trap, at No. 8 on their list, just missing also being featured.

The game received further reviews and general praise upon its release to the Virtual Console in 2009. Website Nintendo Life praised the game's controls for being smooth and responsive, especially for such an old game. The review appreciated its graphics, especially in its sharpness and usage of color; it further lauded the game's upbeat sound that complements the game nicely, the varied level designs and gameplay elements such as the need to answer questions from some bosses, and its overall execution. It said that the game is one of the better Master System titles that still plays good today. IGN called Wonder Boy in Monster Land one of the best games on the Master System, mainly because of its unique balance of platforming and RPG elements, which the reviewer calls "a winning formula". It said that the game is an improvement over its Adventure Island-like predecessor, replacing the "fruit gauge" with an hourglass timer while retaining other elements such as finding invisible items and discovering secret areas. The review mentioned that the game should appeal to fans from the days of 8-bit and the Master System.

Allgame gave positive reviews of the game. It said that game includes everything from hidden items, simplistic gameplay, fun and replay value, and basic but good-looking graphics. Defunct Games called Wonder Boy in Monster Land the most challenging game in the Wonder Boy series, noting the lack of passwords or continues in the Master System version, the relatively few chances to earn extra lives, and a time limit. The review said that the ability to earn gold and upgrade equipment which are laid out in the status screen tremendously adds to the replay value. It praised the responsive, though sometimes not precise, controls and the tight hit detection. Moreover, it said that the graphics were colorful and that it complemented the music and its simplistic sound effects well. Overall, the review said that the game is recommended for Master System and platforming fans alike.