Congratulations on your first game! It’s not easy, especially starting in raw Vulkan over an existing game engine. While I wouldn’t recommend that path, it is cool to see someone try it, and there is a nice RTS foundation here to work with.
I was not a fan of the control scheme, maybe a personal thing but the Shift and Ctrl modifiers weren’t really intuitive and I would constantly forget how to select mid-game. It was also hard to tell what jailbirds I had selected which didn’t help with that either. At the same time though, I also saw little reason to not select every jailbird at keep moving them in the first place. My second playthrough where I beat the game, I selected every jaibird I spawned and brute-forced towards Nerissa (after not realizing she was even there the first playthrough), never used the deselect. Compounding that was the slow camera speed, which made it really hard to keep track of everything in such a large map. I zoomed out the camera for most of the game to keep an eye on jailbirds deep in and jailbirds I just spawned, and it meant I was mostly looking at dots scurrying around.
On my first playthrough, I also noticed jailbirds stopped spawning at the base square at some point despite having points to spawn them. That effectively softlocked me, though I can’t pinpoint what was the cause of that sadly.
Again, congrats on making your first game in general though, hard to put something out there even in an incomplete state. Good work!