I love this game, but I wish the enemies weren't so imbalanced. When 90% are basically a non-issue, but you have one enemy type that bypasses 70%+ of the towers you put in (thus defeating the main point of the game), you've made a mistake somewhere. I think ninjas are worthwhile, but having more health but shorter invisibility would go a long way to reducing the frustration they cause.
I enjoyed it, but was very disappointed to find the save function didn't work (at least not for me -- using Chrome). Now I wish I'd finished it in one sitting.
Having the external site link in the middle of the playfield is kind of obnoxious, and it would be nice if there were a help menu that explained the weapons and powerups. Other than that, it was quite a fun little diversion. Very well put together and clean.
This game is fantastically crafted. It can't be solved with random clicking, and the puzzles take some real thought. There were only two minor parts that I couldn't figure out on my own, and if I hadn't given up, I might have solved them anyway. Way better than the average point-and-click puzzler.
Just plain broken. I got every question right (you can scroll the text by selecting it with the mouse) and the game told me I got 7/10, probably because it didn't count the repeated questions correctly.