I always hate 3 things in that kind of games (my prefer kind of games).
1- Really short waves... When you are putting towers and upgrating some of them to max level, then... the stage is over
2- Really short game. Only a few stages, mostly with levels in towers blocked. And finally, when levels come well, interesting and with full levels for upgrated... yet is the final of the game.. WTF!
3- Not equilibrated (at least the most tower defense games I saw). Why? Because at the start of a stage, sometimes it is really hard, but then, in a second, it comes a moment where the stage goes too much easy... Hard change, start hard and instead goes easy little to little near the end of the stages... it comes a moment when all the stage turn to very easy (only for put another 2 towers more, or upgrated one kind of tower, etc)
WHY when I open the game (and no "new game") my rank is different? I dont clean the cookies, but this evening my rank was 25, now is 1.... yesterday it was 29 ... etc
Is it normal? The rank is cleaned everytime you open the game?
 "Kingdom Rush Frontiers"){kind=icon}
 "Bloons TD 5"){kind=icon}