Banana Nababa!!
There is no current WR that I could find for this title, so it is up for grabs! Go get it.
This homebrew boss arena game from 2007~ is free to play and I will be hosting it here, though you can find it on various gaming internet archives.
It is a simple enough game with 3 buttons: Jump, attack, & change weapons (axe or spear).
Axe arcs and spear goes forward faster. This game is fairly difficult but the bosses are completely learnable!
Joy2Key is okay to use (no turbo*** edit: we are discussing if turbo is okay).
I would recommend watching this LP by kazeugma for information about bosses.