Very solid game, I love the concept of a dynamic tower defense game, I think this is one of my favourite interpretations of the theme and also one of my favourite TD games (even outside of the jam). Please continue working on this in the future, give it more polish, more visuals, more effects, more enemy types/buildings this can just be great - BUT that doesn't mean that it isn't great right now! For 48 hours I won't call it perfect, but it is absolutely up there with the best for my personal preference. I just wish it would be a little more varied. The viusals somehow reminded me of Comand and Conquer which is also a positive memory :)
Keep it up, the idea is great, just expand and polish it! Or in other words you could..... .... Allocate more resources into the game in future :D