This game was meant to be a puzzle tile-based platformer so the jumps cover tile-based distances. You can interact with signs so that you have some tutorials: you've to press ENTER like you interact with NPCs :)
For this reason I think you've not understood the acorns mechanics, which allow you to jump higher if three of them are collected.
Otherwise I know the controls are a bit cumbersome, I'm working on making everything more fluid but the game will remain a tile-based puzzle, so the jumps will remain as before.
For the quit button in options: in the title screen if you click it you can exit the game while during a gameplay session you can return to the title screen. There is a bug in the HTML5 version about the options menu, I'll fix in the next update =)