Get rid of the enemy's ability to fire artillery. War may be hell, but games shouldn't be. I had the perfect start, perfect everything and got blown to bits by the artillery with no warning. It makes me not want to play the game with such instant death. Which is a pity because this game has enormous potential. Just make it a war game, not a war sim.
Nice idea, good art, lousy execution. Levels are too long with nothing happening, especially with so few checkpoints. And then to have to do the same level three times over with little to no variation is downright horrible. Most of the weapons virtually demand you fly into flak, so the electricity one becomes unproportionately powerful. Was there a story? I lost interest in whatever it might have been after playing the third identical level.
The one thing you expect in a typing game is correct spelling of actual words. What the hell is a Yapock or a Pudu? Beyond that, buggy as heck, the combos run too fast so it takes forever to run up a decent score and not only that but utterly boring.
Exceptionately difficult, but not necessarily a bad thing. Fun for a while, one to come back to and play over time.
A bit more variety in towers, buildings and upgrades might help.