I played the game, I found a bug with the fullscreen option in the menu, if you hover your mouse over the letters it will toggle on/off the fullscreen. From the 4 levels, I only beat the tutorial, the physics in the game goes against what my mind feel "it should be", movement is too floaty and the lack of precision playing it with keyboard made the levels harder for me. For example, I was playing the 4th level, the large climb, those narrow paths are annoying with keyboard, so I started using the stick of the gamepad and it was more fun, but still hard, no room for error. I think you should make more easy levels at the beginning, so the player can familiarize with the physics, mechanics and how to deal with the enemies, speaking of enemies, I think an in-game tutorial of how to deal with the enemies would be nice for new players, otherwise they can become frustrated and just drop the game.
Everything else is very nice, UI, aesthetics, music, cute girl.... I like all of that, you really made those appealing, specially for those looking for a retro style game. I see future in this game, but it need more polishing in the gameplay aspect of it. Keep the good work!!!