First off.... how do you manage to do so much as a single dev? That's quite impressive.
The core loop is very strong and it was very clever to break the routine with random attacks , the visual feed is very good, and I think is intuitive enough to recode the interface and actions so when you hit the enemy it understands that attack is the command to execute.
You can break it into smaller sizes for levels and add new difficulties like water you need to evade, or add a bit of RTS with buildings that can defend you while you get more ants.