The particles for the bullets exploding look really pretty! I found myself using both bullets simultaneous since there wasn't a limitation to doing that. It seemed like the enemies would go down regardless of the weapon type I was using; something that you had intended to implement but didn't quite get time to do? But you may want to include some sort of a temperature system, where you can only use hot when you are cool and you can only use cool shots when you are hot. That would make it more strategic to determine when to switch between them. And otherwise limit us from spamming both since that will trivialize the need to switch etc. The visual style is nice and I think that you could definitely build off of this. Having a spawn for enemies that you can destroy is very cool too.