How do you walljump?
You have to jump at a "seam" in a wall, where two wall tiles meet. Then, there is a chance the game will give you a small window to jump. So if you jump again during this window, you will walljump.
Recent runs
You have to jump at a "seam" in a wall, where two wall tiles meet. Then, there is a chance the game will give you a small window to jump. So if you jump again during this window, you will walljump.