That's really simple, but it gets the work done.
I love the slam jump tho, I think it's always amazing to see bugs turned into cool features. Well at least I'm assuming it to be initially a bug x)
Althought as the other person said, the control scheme for 2 player is very janky indeed, and idk why you're expecting people to simply have 2 keyboards avaiable, I can guarantee you 90% of people doesn't lol.