Scoring in this game is relatively simple. It is based on how many critters you knock off the ledges :
Shellcreeper : 800 points
Sidestepper : 800 points
Fighterfly : 800 points

Knocking over an enemy : 10 points

The above scores are for knocking only one critter off the ledge. If you knock off two in a row, you get 1600 points. Three nets you 2400 points while knocking four or more off in a row garners you 3200 points.

You also get points for things other than the above :
Slipice : 500 points
Coin : 800 points
Red Fireball : 1000 points
Blue Fireball : 200 points

In addition to getting points for the above, you also can get points during the bonus rounds :
1) You get 800 points x the number of coins you gather.
2) If you get all ten coins, you get 5000 points in the first bonus round and 8000 points for each bonus round thereafter.

* When you start a game, you will be in the middle almost under the POW button. Your job is to go after the critters entering from the upper left or right pipe. Learn how to jump not only up, but also sideways. The platforms don't have a lot of room for jumping straight up. You need to learn how to jump sideways so you can quickly make it to the next platform. This is both for running and standing still.

* Know how each of the critters moves and what their behavior is. You can use this knowledge to your advantage. For example, an easy way to take care of Sidesteppers is as follows (assume that critter is moving left. Do the opposite of what is stated below if the critter is moving right) :
1) When they are just to the right of Mario or Luigi, jump up and hit the platform. This will make the Sidestepper mad and it will move left again.
2) Right when it passes over, hit it again. This will launch it up and make it drop to the next platform for easy pickings.

* As often as possible, try to kill animals in groups. Any animal killed is worth 800 points (plus the 800 point bonus coin). If you kill two animals in a short time (approx 1 second), the first is still only worth 800, but the second animal is worth 1600 points, not just 800. For three animals, the points are 800-1600-2400. For four animals, the points are 800-1600-2400-3200. The point for a killed animal is never more than 3200. So if you were to kill 5 at once, the fourth and fifth animal would both be worth 3200.

* Also remember that unlike the fireballs, the critters can wrap around the screen. So if one disappears off the left edge, be prepared for it to reappear on the right edge.

* Use the POW button conservatively. You only get three uses in the game, so plan those uses wisely. The best time to use the POW is when a lot of critters are on the screen at one time. In addition, make sure they are close to the bottom when you flip them over or you may not have time to knock them off the upper platforms.

* After you flip a critter over, you have about five seconds to knock it off the platform. If you fail to do this, it will change color and speed up.

* If the last critter in a round is a Shellcreeper or a Sidestepper, it will automatically go to its fastest pace; if it is a Fighterfly, it will continue at its current pace.

* Learn how the critters move. If they bump into each other or a coin, they will reverse direction. You can work this to your advantage by trapping some critters between two flipped over critters. Again, be quick or they will recover and be faster.

* Coins can be collected by either grabbing them or by hitting them from under the platform they are traveling on.

* Things such as the Fighterfly, Red Fireball, and Green Fireball must be hit when they are in contact with the platform. This can make these things a challenge especially when there are other things harassing you.

* Speaking of the fireballs, some players hunt them for extra points. There are some things to keep in mind :
1) The more times you knock off the Red Fireball, the faster it gets.
2) You can escape off either edge to escape the fireballs. They cannot wrap around the screen.
3) As you get into the later phases, the Green Fireballs appear much quicker so you must be ready to get out of their way.
4) Only one Green Fireball will be active at a time, however, when one ends the other can immediately begin.

* If you get killed, you will be placed on a platform above the first gap. You have ten seconds of invincibility before the platform disappears and puts you in the thick of things. Plan your re-entry carefully.

* The Bonus Phases appear at Phase 3, Phase 8, and every 7 phases thereafter (for the Japanese version, add 1 to the round number), and are pretty easy once you get a pattern down. In the first Bonus Phase, you will have 20 seconds to get the ten bonus coins. However, in later Bonus Phases, you will only have 15 seconds.

* The later phases become challenging because not only do you have critters to deal with, after the second Bonus Phase, Slipice will appear in search of a location to plant itself and freeze a platform. Until it manages to completely freeze the platform, the brothers may interrupt it and punch it from underneath. The platform will only remain frozen if Slipice has been given enough time to do its work. After the third Bonus Phase, Icicles begin to form on the underside of the highest platform, and the pipes that sit above it. They will fall down from the upper platform and pipes to add to the hazards you already have to deal with. Using the POW will knock them down before they do any damage.

* When you are playing a two-player game, both Mario and Luigi are on the screen at the same time. (In a one-player game, Mario is on his own.) It is up to the players as to whether they wish to cooperate or turn it into a death match.