I liked your game, I really did! The concept's good and the music and graphics aren't bad. The thing though is that the controls are kinda buggy and unresponsive at times - some times pressing up and spacebar (or viceversa) ends up in a single jump (and certain doom at times).
And that makes the gaming experience quite frustrating...
I am no programmer, have no idea how to address that issue. But what about changing the doublejump keybind? For example, pressing spacebar twice, or W twice. That'd make the gameplay a lot smoother. Hope I could help! ;)