- Charging with Mega Man in bonus areas causes him to disappear.
- Mega Man's horizontal ground and air control are not accurate to the original NES Mega Man games. Mega Man does not have any momentum to his horizontal movement.,
- Mega Man's shortest jumping isn't short enough, and therefore isn't as quick/responsive as the original.
- Elements that move off the screen view are handled differently. In SMBC the elements will pause and wait for the player to catch up before resuming motion instead of simply being deleted if they move too far off the screen.
- You can scroll backward all the way back to the beginning of the level at any point. This opens up many "either/or" decisions in the game. Powerups and other items that would be restricted because of the checkpoint or inability to scroll backwards become available with a bit of backtracking. Finally, the enemy and level layout simply isn't designed with forward and backward progression in mind.
- Spiny enemies that are hit from underneath platforms aren't supposed to die. Instead, they're supposed to bounce to the side, reverse direction, and keep walking.
- Kicking a Koopa shell seems to have a bigger grace window for not hurting the player after bouncing back from a surface.
- Enemies can push each other out of the way when they occupy the same space.
- Boomeranging a squished Buzzy Beetle may harm Link if he then tries to kick it.
- Goombas don't reverse direction when they walk into a squashed Goomba.
- The Mario mid air JUMP glitch (after touching a powerup) has been removed.
- Samus' double jump glitch after unballing has been removed.
- In World 1-2 the Mushroom powerup and/or level layout is slightly off. The Mushroom should bounce off the first stalagmite and travel left, not get stuck between the first two stalagmites.
- The brick hit boxes/player hitboxes are slightly off (at least with Mario). It is much more difficult to JUMP up into a 1 brick size hole.
- Mario is all about speed balanced with just enough maneuverability to give players the ability to blaze ahead, take crazy JUMPs, and make adjustments accordingly. Mario can short hop, full jump, and everything in between. The RUN mechanic makes Mario the fastest character in the game. With RUN and a few other mechanics Mario can SLIDE, BREAK, backward JUMP, DUCK+JUMP, etc.
- Mega Man's slide gives him Mario like speed but with a sacrifice to adaptability. The slide goes a set length, and during this time the player can't change directions, JUMP, or SHOOT. Otherwise, Mega Man's JUMP and air control is about as versatile as Mario's. Aside from sliding, Mega Man moves at an even speed like the rest of the characters in this game.
- Samus' JUMP is floaty and highly maneuverable/variable vertically and horizontally. Going into morph ball allows players to compact their form even in mid air. Unlike DUCKing Mario or SLIDEing Mega Man, Samus can control horizontal movement in this small form. Just ROLL left or right away from danger. Using the advance technique of BOMB JUMPing, Samus can climb higher than any other character (see image above). Slow, steady, and mildly maneuverable, this option gives Samus the ability to explore levels in a unique way.
- Link's JUMP is less responsive than Samus or Mega Man's because of the added degree of momentum. Though Link is small, landing on enemies or specific spots can be fairly tricky.
- Bill can only JUMP to his maximum height. In other words, short hops are impossible for Bill. Fortunately, his horizontal air control is very responsive. DUCK to hit low targets at the sacrifice of mobility.
- Simon has no vertical or horizontal control in the air. When you take a JUMP you're committed to landing in a predictable spot if you don't use your DOUBLE JUMP. Still, this second jump only allows you to make one more adjustment. All platforming must be carefully planned out with this character.
Like or hate the movement of any particular character, the discussion wouldn't be complete without considering their offensive/powerup/special abilities.
- Mario is the only character than changes in size with powerups and the only character that gains a projectile weapon instead of simply upgrading an existing projectile ability. Plus, only Big sized Mario can break bricks. With each powerup, Mario gains new abilities that help him transform the game world and/or undermine gameplay challenges. I explained more of the design of Fire Mario here.
- Mega Man can only SHOOT horizontally, yet his CHARGE shot can go travel through multiple bricks. With his helmet on, Mega Man can break bricks by JUMPing. Like in his games, Mega Man's shots pass through walls and don't stun enemies.
- Samus' shots and bombs do stun enemies. In the air Samus can SHOOT in 4 directions. On the ground she can shoot in 3 (left, right, and up). Her blaster first gets a range upgrade and then a wave property that gives each shot more vertical range and the ability to pass through solid walls.
- Link makes up for his poor control with an arsenal of versatility and nuanced ability. The Boomerang can retrieve coins and powerups as well as freeze enemies. It can also be thrown in 8 directions. Link's sword can be held out up or down in mid air for protection. Since the sword stuns, Link can bounce off of multiple enemies in mid air while freezing them to create a unique kind of aerial platforming in SMB. Finally, Link's final powerup state shoots out a energy sword projectile horizontally.
- Bill is very straight forward. He can SHOOT in 8 directions. His bullets pass through solid objects, and they don't stun enemies. With more powerups he gains more firepower (see image above). His somewhat limited JUMPing abilities and lack of bullet stun influence players to dance around to get clear shots. Though the spread shot looks all powerful, each bullet isn't very strong. For maximum effectiveness, you have to move in closer to the target. This design creates a "close in or dance" dynamic.
- Simon's whip becomes an incredible range attack when fully powered up. Still, the axes are difficult to aim (much like the Hammer Suit powerup in SMB3). With slow movement and the most difficult JUMPing maneuverability of all the characters, Simon is the most difficult character to use.
- All characters can JUMP on enemies like Mario. This keeps the basic gameplay very Mario like, which is essential because the level design is still Mario. It also shows players just how difficult it is to "do the Mario" for other characters.
- Because everyone can JUMP on enemies, projectiles can be weakened. Mario's fireballs are still the most powerful projectile in the game. Every other kind of projectile is either weaker, requires a charge, has less range, or some other kind of functional drawback.
- Being able to retry each world instead of having to start over from the beginning is an excellent design choice that gives players the freedom to experiment with other characters. After beating the game, a level select option would be nice.
The final points I want to end off on are issues of balance and design space. Mario's classic gameplay is mostly made up of 3 layers; Mario (the player character), the level structures, and the enemies. Take Mario and put in any other character, and you'll still have challenges that are mostly Super Mario Bros. challenges. What I find immensely enjoyable about Super Mario Bros. Crossover is how the same layers of level and enemies create very similar, familiar, yet new challenges when played using different characters. Surprisingly, even the projectile heavy characters that can demolish bricks and enemies from afar still yield very Mario like moments/gameplay challenges. It's like magic. You can discover more Marioness out of SMB by playing other characters. Who would have thought? And the best part is, as I've highlighted in this article, every character takes up a unique design space size, movement, and ability wise. I guess that only comes naturally when you plug in characters from completely different games.
I'm afraid that this game won't last forever on the internet. So grab a piece of history and learn about SMB's history before it's too late.
A quick video I made of some neat tricks/plays.