This brought up nightmares of high school chemistry! Well done on a clever chemical twist of classic games. The first time I played I sucked, but the second time I got to level 9 with a score of 25010. Eventually I stopped getting antimatter balls (whether that's by design or just random misfortune) and that's what killed me in the end.
I think I encountered a few bugs during gameplay where sometimes atoms would fall through existing ones...it was hard to reproduce.
I'm sure it'd be impractical (or maybe impossible...I wasn't the best chemistry student) but it'd be neat if you showed me which molecules I made the most at the end of my game (and could name them!)
A solid entry into the jam!