It’s a real classic. It’s a great game and I am waiting for it’s newest incarnation: The New Super Mario Bros. for my also awaited Nintendo DS lite. Besides that: my apologies that the animated gif is 10 pixels wider than usually.
and allows to jump again, boosting from the wall. In the example image on the right, three walljumps are performed.
Theory: Walljump happens because the game does a floor check (a simple “is position divided by 16 even? Is there a solid block below him?” test) even during a wall-ejection. Wall-ejection is SMB’s mechanism to adjust Mario’s horizontal position properly when his left side and right side have a different inside-wall status. The game ejects Mario towards the opposite of his steering.”
To perform a walljump, you need two things:
- Some horizontal speed (towards the wall)
- Mario’s feet must hit the wall exactly at a block boundary (every 16 pixels)
It’s possible to perform walljump from any non-lethal solid material (bricks, pipes, etc).”
Source: Super Mario Bros. Tricks