There's only two issues I have about this.
This game is atmospherical and fun. As some of the others already mentioned, you take minimal graphics to a maximal level of awesome. Sure, this game is not the right place for upgrading the hell out of your tower like in other defense games, but as the title implies, I have two issues with this game:
-I don't know if anything new happens, the "Watch all ingame cutscenes" achievement suggests the opposite. Under these circumstances, it's impossible to overheat your gun, making the engineer upgrade "faster cooldown" useless. You could actually include upgrade phases in the nights of the game imho, but only upgrades like faster engineer/mortar increases or a quick reload special skill against these moments when you just shot your last bullet and an airplane appears. That way, the overheat could be way more evil at the beginning, but with upgrades, you could achieve a level of overheat close to the current one.
-The second issue: The game is too short. Sure, it's infinitely long, but you have too little trust in your atmospherical talent. After 48hrs, it's done. No more tragedy, no more drama. I would play the game much longer if there was more of the atmosphere that you have created, but there isn't. The "each achievement gives an own cutscene" feel was great, so why not take it further? If it really was true for every achievement (and upgrade, if these were to be implemented, for example as three-level-perks, one upgrade per night), I would probably play the game over 10 times just to see all the cutscenes.
If there's ANY chance to motivate you to actually re-release your game or add another mode (arcade mode, so to speak) with similarities to what I suggested, I would dearly want to do so. This game is exceptionally fun, but there's a lot of potential still behind it.
