There's a weird bug where I sometimes die at the very start without doing anything. Sometimes the sword doesn't hit even though it looks like the sword has definitely went through the enemy. I also know that it's a game jam, but if you make a game based around doing the same long course over and over again until you get till the end, some random generation would be nice. It doesn't have to be entire world generation, but it could just be a bunch of possible enemy spawn positions, and you make a specific or maybe even random number of monkeys spawn in any of those positions (of course there'd be more detail than that if you'd do it, but that's just my general idea). The enemies also feel a little boring because they just stand there and do nothing, giving no challenge. Simply programming simple AI for the monkey to follow the player, and jump when it sees something on its side would probably be enough to make it much more interesting. There's also no sound, so that's a bit of a stinky.
Other than that, great art, slightly frustrating platforming, but sometimes that's important for fun, and I see a lot of potential in this!