I unfortunately was unable to get past level 2.
I quite like tower defences, but the limited choice of towers (at least up to level 2) limited the strategic depth. Additionally, tower defence usually features upgrades which were here missing. This further limited the available options.
This overall makes it so I don't really have an idea of what I could have done better to perhaps beat level 2.
The art is excellent.
I hope to see this concept revisited one day. There's probably something to be made for an SRPG-TD.