Disclaimer: I fully understand this is a game jam game not everything can be done but even then I give very "tough" feedback so if you can't handle that kind of "criticism" it's ok just don't read my message.
The tutorial I believe could be improved in the sense of the text being formatted better as for example there's only a single page saying "WASD to move" while another ends up being quite a paragraph
I didn't end up needing to use the Turn up the Heat mechanic until close to the end, I won't lie that I did see this game played already in streams so I had an idea of "how to win" but the end can still feel like an endless stalemate without the use of the Turn up the Heat so I would advise in my opinion to remind the player that it exists in some unintrusive way shape or form if they haven't used it in quite a while.
The enemy (and ally units) variety could be expanded upon even if it's just 3 more enemies and ally buildings/units for more variety and 2 enemies is already more variety than most but just something I wanted to say if planning to continue to put time into this.
It's quite unfortunate there's no music so don't pass it up for next time.
The visuals felt slightly too bright atleast in my opinion and the sound effects were slightly loud too, I recommend to do even something like slight pitch randomization alteration to not have the same sound effects at the same pitch play out every single time.
All in all I might have forgotten some things but it's fun, I like the concept, turning the usual TD into a more real time strategic approach.