It's a really great game and I love how you managed to turn simple collision mechanics into something really interesting to use. Though pushing boxes around got a bit frustrating at the alien level (couldn't figure out what to do at first and then got stuck in a box when it flipped after falling while I was inside) and the level right after (which I couldn't finish due to having to restart the 3rd puzzle multiple times), but I really like the whole idea and the way you bring back some mechanics after introducing them in a simpler environment, figuring these things out was the most fun part about the game!