The physics added an extra layer of complexity to the game that was fun to interact with. For example, it felt fun when a sonic shield or missile explosion would send everything way back up to the top. The spread blaster could also be used like a tractor beam on the sides at certain angles. I really enjoyed the game loop and am still curious about figuring out the best upgrade strategy!
The one design choice I wanted to call out was the assembly points system. It felt bad having the 1 assembly point get wasted every round as I was struggling to keep up with scaling enemy health. Having an incentive to not reroll or making the reroll a separate currency would have made it feel like I was getting maximum value each round.