This is a really cool concept! Huge kudos for getting it to such a playable state, especially as a solo developer, in four days, and your first game jam! With some visual and UI polish, I could definitely see this evolving into a fun and engaging strategy game. It might even be interesting to explore turning it into a card or deck-building format!
A brief tutorial or even a simple text screen at the start would go a long way in helping clarify the mechanics and overall goal. But all in all, great job on your first submission - it’s no small feat to create an entire game in just a few days! Hope to see you continue with game jams and keep improving your skills. :)