The idea of attacking a tower defense makes it quite different because now you can observe and plan how to tackle the attack, like a tactician!
The game can be executed better like placing units and having a “GO” button, and both the units drain being faster. But for anticipation, it could work!
Nonetheless, I enjoyed my time playing the game! Finished it too~ I’m not sure if stacking the units is the dev intended solution though. …and ouch stacking shooting sounds hurts my ears…