The concept is not complex enough for me to judge so I think you can just expand the game with more towers, more enemies (both stationary and mobile), some new kind of resources, environments, upgrade systems and so much more. Awesome to hear that you are going to publish this promising piece to Steam, I will check back some time later so be sure to update your progress!
For sure there will definitely need to be more towers, as they will keep the game more interesting. I'd like there to be some kind of rock paper scissors balance of abilities for these towers. Mobile units is an interesting concept too, you mean such as factories that produce units that can fly away from your base?
I'm glad to hear your enthusiasm, I will for sure be developing this further. I assume you'd be interested in beta testing?
I will be posting updates about it on Discord and Twitter, and I've gone ahead and set up a Gamejolt page for it here! But first I must complete my current project, which was an entry for a different Jam.
