This was my first jam, so I'm just impressed that I got mine even close to "a game".
The day before submissions closed, I had a bunch of stuff that was sort of working, but it was all disconnected and run through a debug menu, so you were basically playing against yourself. Day of, managed to get the computer to fight back, and added an upgrade system to give you a little bit of choice in how you're building.
There's a lot of stuff that I would have liked to have added, more levels, some bug fixes, more enemy types, sound, etc. But some of it I didn't have time to learn, and some of it I sacrificed for more important stuff. Next time!