I like mechanic of destroying other base! That chain "boom" has some juice!
I appreciate how you managed to make so minimalistic art but enough to have fun, this kind of retro style make game more shine
To improve probably could make some more obvious how expanding your base, event just some popup with information that you must to gain more resources by attacking other base. From experience ppl rather are not patient to read and understand text instructions :D
That concept is great, because mechanic of gathering resources has a lot of possibilities.
Great you did take care of adding extra text to explain game, that still helps ppl who want to put more time to understand the concept
Good job and congratulations on your submission!