This was fun to play. It took a bit to figure everything out, but then I started to make progress.
When it started, the left edge was cut off on my screen. The "E" in "End in" was split about down the middle. I looked for an option for fullscreen, but did not see one. I closed my side panel and was able to fit everything on screen, but it felt like the panels on the left crowded the screen on that side, and made targeting enemies coming from that direction difficult. I eventually maximized my browser, and I'd say this was designed to be played in 4K. Things definitely looked better spaced and sized. Not everyone plays on 4K screens, so it would be good to add some scaling to be more playable on at least 1080p, especially for a jam. We do use a 4K screen when playing jam games as a group, but solo is often on 1080p.
I like that placing the wall tiles keeps you on them until you cancel. It would have been really annoying to have to press the keyboard key each time to spawn a new one. One the other hand, when I went to place the houses after doing a bunch of wall, it too me a moment to realize they were not working the same way.
My first playthrough I somehow skipped the towers. I followed the instructions to get a mine up, and explored a bit, then felt like I was constantly being swarmed and did not get a break during the day. I built some walls, then did the houses for the goal, before trying to find the enemy base. It took me far too long to realize the rocks were spawn points that needed to be destroyed. Only once was I surrounded when I explored a bit too far and came back toward where there were extra enemies waiting, but never really felt threatened. It was easy enough to take out the enemies. They also seemed to favor me over my base, so I built some walls, and then left to explore, and even when off to one side, they came for me, rather than my unprotected base. The enemies also favored coming in a line, which made it easy to just spam fire it their general direction. A bit of variety in their movement could help. When I finally tested the towers, their firing seemed to come from an odd location away from them. They still took out enemies and worked fine, it just looked odd, and could affect where they need to be placed.
I ran into a fair amount of stuttering by day 3. It was still playable, but noticeable. On day 9, with 88669 minerals and 11 houses, the game locked up. The console shows these errors:
ERROR: Condition "_data->size_cache" is true.
ERROR: Parameter "mem" is null.
Overall, its a good start. I plan to give it another try using the towers to help not feel so overwhelmed, and allow me to push forward.