Not a bad game, overall. Though I did find two typos. One of them is at the end, where it says to tell you if we find any "typoes". I can't remember where the other one is, but it's there.
Wow. Kind of fun at first, but then it got too easy. I got 470,237 and lost 6 health, but that was the first time through, and I didn't have enough fire towers. Definitely needs some improvement.
To anyone who doesn't think there is a save button:
You're right: There is no save button. But, it does save your game. As long as you keep playing on the same computer, and don't clear out your internet files, your game will be saved. When you start the game, just press the right arrow key over and over until you get to the first level that you haven't solved yet. It will stop when you get there, so just keep pushing until it won't change levels anymore.
When a small square is moving back and forth every so often, that is it giving you a hint. There is a difference inside that little square.
It won't happen if you play without hints.