While I don't tend to like tower defense games, this one had a pretty unique spin which was nice. I play a lot of Arknights and could definitely see the similarities, as that's pretty much the only tower defense I play because of these unique mechanics.
I liked that a lot of effort was spent in building up the identities of these characters rather than leaving them as emotionless husks, but it may have gone a little too far and I found myself skipping a lot of the dialogue as I wanted to get to the action earlier. I think making the dialogue skippable would work it work for both types of players.
Nice artwork as well, although the map looked a little low res and the characters and buildings look like they have been scaled down to fit on the screen therefore the quality degraded around the edges. Try playing with vector art that scales to any size. Well done though, great work for only a month!