Afireinside8477, I was able to beat level 10 by using nothing but laser towers in the middle section. On one end, put a ice element, put another ice element on the far end, and a fire element in the middle. Make the section combos. There might be a better way, but that's how I did it.
Chrome gets you money quicker, but it's kind of dumb to take since it just takes points away from defense and precision. Another big complaint I have is that fights take way too long by level 50 or so. The repair option doesn't add strategy, it just drags fights out. I've never used it, and in my newest game I haven't even had a hit taken against me, but the CPU uses each of those damned repairs and drags the match out. Then once it's used up it's repairs, instead of fighting, it just waits.
Even on the hard setting, it's very easy. Just spam defense and precision, occasionally put some into grit, and buy upgrades when they become available.
Got all the badges, don't have to play this damned game anymore. Thank god.
Note to anyone thinking the AI is overpowered... they are supposed to be. Wouldn't be much of a challenge otherwise.