I think the big challenge here is going to be how to mix the metroidvania and tower defense sections. So far, the player control feels really clunky for a metroidvania, but is actually suited well enough to the tower defense sections. Personally, I would simplify the mechanics of both sections as much as possible to avoid overwhelming the player with systems to learn, since they need to master both sides. Another issue you might run into is if the player is better than the towers - for most of the first conflict I was able to do well enough without towers by just using my main attack.

It's an interesting mix, but feels really early at this point. Hope it works out well!