Boringly easy AI & challenges. Make it multiplayer and it has potential.
(add max hive mind, hrathian bot, pincer bot, r3 sentry, 18 cards win all challenges. Restart match if you start with more than 2 sentries.)
This is approaching AoS (pre-DotA) gameplay. Fived! Need consumables: 5-20 ether for a base patrol ally, temporary increase to attack rate, shield recharge, etc. 50 point upgrade: remaining ether is bonus percent increase to your damage.
Simple, fun, painful. Good indicator for people wondering if they could be a programmer. Be warned, real programming has many functions and commands that you spend a lot of time memorizing before you start programming the robot.
This game is too easy. Everything else is good. A way to get money while waiting for enemies was a smart move - be careful not to shovel good building spots. I would have liked to see units upgrade paths and range/damage before buying them.
Sometimes green arrows are good, and sometimes (final level) they just fling you into a spike. So then you get to restart the level and make a mental note not to do that. That is not a challenge, that is annoying.