Pretty cool and simple game. The graphics are pretty neat. However, this game suffers from two problems, it is a bit too easy, like you can spam spacebar and you are basically unkillable, and the enemies drop the items that lower the temperature pretty often. The second is that it is a bit repetitive... maybe more upgrades, or boss fight.
But overall, it is a pretty solid game and is pretty polished, I didn't find any bugs.