Loved the menu and inserting the cassette to play. Really creative!!
It needs a little bit of polish here and there (baloon in tutorial, after walking in an inclined surface the players jumps after as soon as you stop walking, etc) and some controls improvement and flexbility like adding arrows (found it quite hard to play with wasd and space).
Besides that I really liked it, the bosses were crazy! hahah Would love to play more levels. Good job!