This is cool, all around very clean and polished. I like how crunchy all the sound effects are, it makes things feel really retro. There's a surprising amount of music in here which is impressive too. The last part where you have to destroy your own ship is a really clever and fun idea too.
I wish there was more to the temperature mechanic though. If there was some reason to keep your temperature high (Maybe you move faster or do more damage or something like that) without overheating I think that would take this to the next level. Because right now the temp mechanic effectively just makes your gun burst-fire.
Great job overall though! I enjoyed this one.