Cheats can be unlocked in Super Mario Bros. Crossover by fulfilling certain conditions. Below is a list of all of the available cheats and how to unlock them.
Yes. There are some, so play the game to unlock them (or position the mushroom next to the "Enter Code" option and enter the konami code)!
Cheat
Description
How to Unlock
Level Select
Allows you to select any level from anywhere
Finish both games on Hard difficulty
All Ground Is Bricks
Turns all ground peices into bricks
Finish Super Mario Bros.
All Hammer Bros.
Turns most enemies into Hammer Bros.
Finish Super Mario Bros. Special
All Weapons Pierce
Defeat armored enemies with projectiles easily
Defeat 200 armored enemies and finish the game on any difficulty
Always Break Bricks
Bricks can be destroyed no matter which form you're in
Break 1000 bricks and finish the game on any difficulty
Bouncy Pits
Causes characters and enemies to bounce out of pits
Stomp 200 enemies and finish the game on any difficulty
Classic Simon
Causes Simon's jump to become stiff, disabling air control
Always unlocked
Classic Screen Scroll
Prevents the screen from scrolling left
Always unlocked
Classic Samus
Prevents Samus from crouching and morphing into a ball while in the air.
Always unlocked
Everyone Can Stomp
Allows everyone to stomp on enemies
Always unlocked
Evil Hammer Bros
Causes all Hammer Bros. in a level to chase you immediately
Defeat 50 Hammer Bros. and finish the game on any difficulty
Extra Checkpoints
Adds more checkpoints in levels
Finish a castle
Infinite Ammo
Gives you unlimited ammo (includes SOPHIA III's hover)
Collect 200 ammo pickups
Infinite Lives
Gives you unlimited lives
Finish the game without continuing
Infinite Time
Removes the timer
Finish a level
Invincibility
Makes you invulnerable, allowing you to run through enemies
Defeat 1000 enemies and finish the game on any difficulty
Water Mode
Causes you to maneuver as though you are underwater