A good game, but has flaws
The game was well done. The images are nice and the towers look cool.
Unfortunately, as was mentioned by Valisun, the repetition doesn't make sense. The game has a very steep difficulty curve, with the only way to beat new levels by repeating the previous levels over and over and over and over.... you get the idea.
Also, though the upgrades are good, you punish the player for buying lower level upgrades.
For example:
Initial Money I costs 5 upgrade points. Initial Money II costs 10 upgrade points.
If you get initial money I, it also unlocks Initial Money I. This is fine by itself, but if the player buys Initial Money I, then Initial Money II, the player must spend 15 upgrade points. Thus, 5 upgrade points are wasted.
This may be avoidable in the early game, but in the late game it becomes a serious problem. Especially when you start talking about hundreds of upgrade points, and needing to upgrade as fast as possible to get out of a level.
It is this, paired with how rapidly upgrade's costs increase, that makes the game seriously repetitious.
The Expert bonus is great, but only to a certain point. Again, in the early game it starts easy to get (I got expert the first time on level 1 - It wasn't that hard) but then quickly progresses to being incredibly difficult and pointless. Perhaps a different idea would be to reward the player by scoring how he did on his level, and distributing upgrade points accordingly.
Perhaps some of those could be:
Weak Tactician (*1 upgrade points)
Good Tactician (*1.5 upgrade points)
Great Tactician (*2 upgrade points)
Expert Tactician (* 3 upgrade points)
Expanding further on that, perhaps the level could add score based on how much cash was left over at the end of the mission. That was never factored in.
Now, on to power-ups.
As with most TD games, Power-ups in this are pointless. The bombs cost TONS of upgrade points to upgrade, and generally are left unused. One could argue that they could be useful when facing large groups of enemies, but that doesn't happen often enough. Whenever I use them in addition to my towers, instead of just using my towers, I tend to lose the battle.
Of course, there is also the part about the special towers. I think they are a good addition to the game, but generally fall short of some of the other towers in usage. Why use a poison tower when you can use a basic or rapid tower, upgraded a few times? It tends to be a better idea to go with the latter, which kind of leaves your tower variation rather flat and boring.
Though this seems like a lot of critique, don't get disheartened! You did a good job with this game, but a few more things could be tweaked to make it more interesting.
