Also, if you're interested in another VERY unique (and absurdly challenging) tower defense check out Metalix. It's japanese and worth it's weight in inspiration for sure. Can't wait to see further updates and/or installations of this game!
Great work on thinking outside of the box. This is a fresh take on tower defenses I haven't seen before (I've played a LOT) and it's well implemented. I hope you receive enough support to continue with this series and improve upon it!
What you have is good so far. The boost/break is a good concept. I see no point or end to this game, however. Some upgrades, unlockable levels, or even high scores would help it a lot. Keep up the good work!
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Thanks for the feedback! Will be working on adding upgrades in the coming future.