WASD, space key, and arrow keys to move. (If you want to make this easier go into the editor and chop off the left leg of the cat.)
This one sprite platformer made entirely by me (@Dev_GP) utilizes the clone feature to make this possible, this is something I've never done before until now and I find myself decent at such considering of how simple it really is, but I'm horrible at making textures and other sorts using the Scratch built in draw thingy so it sucks horribly.