I stayed and played this game the entire way through. This is really addicting, and takes a lot of thoughtful strategy to beat! The graphics look nice, and I love your animation work!
For future scope, I would look into the replayability concept of it. Have levels with different objectives, and have more variety of upgrades possibility. I don't know if I would play a level like this again unless there were more challenging upgrades to get. Maybe you can also have the robots break, which would cause more obstacles.
This is just feedback if you want to go further. For the work you did in 48 hours, you should be proud of it! The artwork looks great, the game plays smoothly, and the level was fun trying to find a strategy to build the robots and gather resources. Way to go!