Here's a fun "alternative" way to play this game. Play it like Tetris and leave a column open, I like leaving the middle one open, and then only dropping things down there when you want/see a cascade of combos.
"After about level 4 the game quickly becomes "Oh, I'm sorry, you didn't upgrade in the right order. Now you lose.""
This is kind of the point of this type of game...
It's interesting that games constantly get "too easy" and "too hard" comments. Personally I liked the difficulty here, couldn't pass every level the first time, but never had to do one 3 or 4 times either (unless I wanted to). Not every build works for every level - and you need to plan ahead - buying all fireball is going to get you into trouble later.
Decent game, just too buggy. Way too many towers have trouble tracking or something and instead of firing they just turn and turn and turn until the unit is out of range.
Yea, I don't know why, but I can't get Slow Time to fire immediately, I have to fly around for 2-3 seconds clicking madly before it goes. Guess I will start over, waste of 40k.
Some of the Flash ads on here take up a lot of memory, which can also affect your gameplay, so try reloading the page if you get one of those ads that has a lot of movement and crazy effects.