Overall, for your first game jam this is a very solid base. You should be proud that you were able to get a playable MVP out, despite your lack of time. Everything's there, from player movement to the potential upgrade/attack system, as well as a simple enemy AI.
If you're planning on taking the project further, (which i think you should!), then I would suggest focusing first on your main mechanic, which is the upgrade/attacking system. I think it shows some promise, but I will warn you that it is very hard to balance a playstyle of "Avoidance and strategy," with fun gameplay, as nine times out of ten it results in the player just ignoring enemies rather than engaging with them.
Congratulations on getting a game out for the jam (haha), and I wish you luck in your game development journey!