Very solid nice puzzle(?) game! Gameplay was good and challanging enough I think. Though I did play only the first 3 levels and checked what the fourth key would look like, I think there's a nice progression as well. I agree with some of the other comments here that some sound effects would do great things for this. And maybe some particle-effects when you're drilling the key, so that it would feel you're actually drilling metal and not butter. But hey, it's a jam game, and a great one at that! Nice job!