WASD or arrow keys to move, but I recommend arrow keys because WASD makes wall jumping weird and makes jumps harder. So use arrow keys if the level is too hard. Don't touch the spikes. If you're finding it hard, some levels will be made easier if you purposefully ram into the white line on the left. That will spawn you higher. For example, on the 'Why is it so hard?' level, by ramming into the line, you can skip it. NOTE: Sometimes your character will disappear on the top edge by jumping too high. Try controlling it back down, or press R to respawn. This is my first platformer so it has a lot of glitches. So sorry about them!
Code credit to @darthajclark: https://scratch.mit.edu/projects/379493957 Music is Darkness Keeps Chasing Me by Grace VanderWaal.