Made a reply there as well.
I think you can go a lot of ways. Perhaps a few ideas:
* Different type of enemies like kamikaze or flying that are hard to stop for more late game difficulty.
* The farm felt a bit simple now, not sure what you mean with the farm is the man defence, the farm is the tower that shoots as well?
* I think this would also be great for touch screen, I tried it on my smartphone, but I don't think it was intended for that one
*Small improvements:
- If the cursor is not close to the cards have them drop a bit lower (for more visibility)
- Able to destroy (or sell) building yourself
- Bank is a bit overpowered (see screenshot :P) perhaps max nr of banks.
Also I will be following the game.
