fantastic
this is a lot of fun.
it's also incredibly cute.
i smile at the adorable little enemies before i blow them to smithereens in little balls of flame/ice/arrows/explosions/blood.
i also like the idea of having to power everything up and so on and so forth.
if you do a sequel, since your drawings are so perfect for this and pretty fantastic on their own, could give us some more graphics, maybe? like, an upgrade is visible not just in the number, but on the building as well? that's all.
i'm happy.