This is a classic costume-based Scratch Platformer Game. It has many excellent features, such as enemies, spikes, jump-through platforms, wall jumping, rotating platforms, keys, doors, secret passages and lots more! Use WASD or arrow key controls to move. To wall jump, jump on a wall and then jump while pressing the key in the opposite direction as well. Make sure not to keep on holding the jump key.
Thanks to @griffpatch for his fantastic platformer series tutorial on YouTube and for the thumbnail. The rest of the work is all by me :D.