I like this game but there are a few problems. It is too easy. I've noticed the enemy team barely ever puts out more than 3 or 4 solar towers and never sends very many units at once. It is very easy to over power them. I really like the art work and music. There is a glitch that causes my team to have the same sprites as the enemy team.

The enemy team needs a more cunning ai, like putting out more solar towers and trying to catch the player off guard.

I have played dozens of games like this over the years and seen many times more. There is nothing distinguishing this game from the others of the genre. Nothing there is absolutely no new or creative improvement.

Upgrades were completely meaningless. Even after buying all turrets and most units the same strategy that worked in the first level still works. Make as many solar panels as possible. Spam one cheap unit enough for it to get through the enemy turrets. The only difference to the first level is that I'm now using P90s instead of Glocks and Eagles.
Summary:
Very old and used game idea: 2 stars basis.
Absolutely no improvements or engaging creativity: - 1 star.
Upgrades are completely useless, rendering the whole came utterly boring: -1 star

Constructive Criticism:
Make the Missile Launcher and Ultra Blast more effective. At the moment they are not worth building. Give the player stats for all units in order to allow informed planning. Make the units more different. Include area of attack units, for example. Include different terrains, it's boring to visually and strategy-wise play the same level over and over again.

A nice game, But could use a bit of work. I found out quickly that you could overpower the enemy quite easily (Even on the later levels) by simply stocking up on Solar Panels and mobbing them with Famas troops. Or with Sniper troops. It's a little unbalanced in the side of the player, And the retro graphics seem to... almost.. Degrade from the experience. I recommend 32 bit sprites. Maybe a little more diversity. The troops, As they advance, Appear to not have any specific uses, The Desert Eagle being better than the Glock, The P90 being better than the Desert Eagle and so forth. Maybe troops should perform better against specific enemies. (If they already do, I didn't notice. .-.) All in all, A good game, Worth a play.

Second level, by the time I generate the first energy the opponent has already made two panels and sent half a dozen troops which then proceed to kill me. Related, it should NOT take 30+ seconds to restart a level.

This is a fast-paced strategy game with TD and man is it fun. The upgrade for health is a bit over kill because you can just keep buying it at the same price and in 5 levels I had 4500hp. The radio broadcasts makes this game even more interesting. Good job on the game.