Thank you so much for your very detailed and nice review! It's great to see that you enjoyed it so much to figure out the entire currently available meta! ^^
Indeed this was done in two weeks for the roguelike game jam and as you noticed correctly, there wasn't enough time to balance the things that require a lot of playtesting, especially the late game. I agree that the "Almost everything scales exponentially to the infinite" (for both enemies and units) approach needs to be a bit adjusted to offer more choices and tactics.
Along with your ideas, more content like boss variety, permanent unlocks/upgrades, more and randomly generated maps are all things we could add for a complete version.