5 stars: This is a well balanced, challenging and fun tower defense game I've played. Levels are interesting and there are quite a few ways to advance based on your preferred strategy.
5 stars: Not bad for an old school TD game. Graphics are rustic but I the sound effects are cool. I have a feeling this game will grow on you. Not overwhelmed with Ads or Pay for Upgrades. Might hit me later though. :-)
4 stars: This is one of the better TD games. It could use a speedup button, and the passive upgrades in the world map are laughably expensive, but the levels are well designed and the game feels balanced
3 stars: No unavoidable ads, cute graphics. Just a bit too easy - all levels can be cleared with just one tower type. Annoying that sometimes random bosses are added, but then they are gone if you replay the same level.
3 stars: It's fun but I dont understand the collections or rewards for combining them. I've done it like 5 times and it tells me nothing and dont notice any advantage it gives you for doing it. Other than that it is okay.
2 stars: unbalanced, towers just not effective against some targets. you can grind away or P2P. no speed up option and lots of ads. deleted after three levels.
2 stars: Upgrades are terribly expensive. I can only upgrade 2 towers and the archer tower upgrade is just to sell and get more money. Not even an upgrade. Uninstalling!
...