Wow, this is such a unique idea, especially fitting with the combine theme! At first I was really enjoying playing it, and finding out the best way to combine and separate things was a lot of fun!
I think the next thing that would really polish this game is to add some sort of rotating animation. I was getting kind of sick looking at the teleporting blocks and it got difficult to keep track of how things were turning and where they ended up. The other major thing for me was that it was not very clear that each level had its own unique area to fill up. I think this is a great idea for the game, but should be made a bit more obvious.
This is an extremely impressive first jam game though. I hope you keep working on it and getting more feedback, I think it is very promising!
Keep making games!