I know it's a prototype, but the controls are really horrible... The height you get from the first AND second jump is seemingly random, the jump sometimes doesn't even work (sometimes it doesn't work for no reason, and other times, it's because you're standing on something you're not supposed to jump off of, which is a little stupid in a platformer game). The most reliable way to jump is to spam the space bar which makes you go way too high up; therefore, you can't see the platforms you're supposed to land on and you have to guess where it is. This is both slow and kinda luck-based, making it a very annoying experience overall.
...Though I have to admit I like how the game looks. If it was possible, I would have given this prototype an extra half-star for that.
(by the way, if anyone's wondering, there are in total 4 levels, if you win the 4th level the game just loops you back to it, and if you die in said level you go back to the 3rd one)