Very underrated.
First off I love the art of the game, it's very cute and aesthetically pleasing. Definitely one of the most artful TDs I've seen. There are a few faults like the fact I have to move around the board to see, I think the game would benefit from a zoom out feature. But the reviewer below says the game is too fast paced and I really don't see that as being a flaw. Sure there's no pause button but you can slow the game down to .25x, and trust me that gives me a lot of time to set up things when I want them to. I think the pause feature is fine in a game but it's also a handicap to allow the player to take their time. With this it reminds you to work quickly and makes the game more challenging. Also I like the fact there are different elements that you have to defend, it adds a uniqueness to the game play. Anyone saying they don't like this system is too coddled by the basic TDs.
The one thing I'd also recommend is making the tutorial a bit clearer. Nothing really mentions how elements have weaknesses, so the first time I played the level it was a bit confusing.
And another person said upgrading is worthless, and that's only true depending on how you want to play. There really is two ways to play this game: have strong upgraded basic towers or farm small ones to get to the bigger ones. To each their own.
I'm not sure why this got such a low score but you got a good score from me. Apart from the screen restraint and maybe a weak initial explanation of how the game is played I found it quite original, creative, and enjoyable.