Very interesting game and pretty hard, 8/10 for the kind of game that it is. Fun, free, short game for a school project.
The Good: Towerdefense ++. The combining of towers is great(though I wish there were more options in combining) but the choosing between fire projectiles or fire aoe is amazing player power. Different enemies that need different towers to counteract them is a classic. The little waddle of the enemies is very cute and gives them a little bit of "life". Great difficulty where you have to think a bit about what you have to do to win, aoe is the best.
The Bad: in big bold letters QOL!. You can pause the game but not build while pausing(which is the main reason why you want to pause). It doesn't show how much it costs to sell a tower. I only noticed combining towers was a possibility after 4 rounds so that could be a little more obvious. Doesn't show how much damage an enemy is gonna do before it hits and they all do the same amount so that is kinda meh.
The Bugs: sometimes arrows go through enemies? Idk if that is a bug but it is very annoying. In the second(?) level the 4th or 5th wave just spawns 1/3 of the way there making it very crowded all of a sudden instead of the slow march. In the last level halfway through the amount you get for killing enemies is way less.
Overall good game, actually enjoyed playing it!