The idea was good, but it faired quite badly. Such kind of defense game is quite common, and using factory at that is quite uncommon, hence the credit is yours.
However, the game is problematic:
1. You should be able to sell the turrets, the plot of land is already yours, why would you need to clear it?
2. The cost is constantly rising, well that i understand, but the rising isn't very logically done. Every factory you buy or every clearing you do, will increase the cost very significantly, is that the correct way to present the game this way? I beg to difer!!!
3. No soundtracks or sound effects. Thats a very important soul in defense games like these. Playing in
silence means nothing to such games, makes you feel bore faster.
4. Did you tried to enact the idea from Starcraft or something where you tried to create the arrow button for us to surf around the screen? It's quite troublesome yet irritating at the same time.
5. Lastly, the gameplay is really weird, the flexibility is really low inversely compared to the creativity of the game itself. You should give more felxibility to the game, instead of just tiling the shooters or what, make them placeable anywhere that is cleared. Likewise for your turrets, you should allow upgrades instead of auto levelling up, if not, thats really had to predict when will it level up, cause some turrets shoot more then the other.
6. The game is too big, resize it.