Not bad. For the most part, pretty easy. Several levels, first instinct got me 99% (actually 99.9% but no use nit-picking) and a couple (including the last level) instinct got 100%
The main problem I have is with Level 22. No matter where I put the two upper towers, I get no more than 99.9%. And one pixel would drop that 99.9% to a 97%-counting score (I think 98.5 or so, but wasn't paying attention).
Which is odd because I used straight-edge calculation (well, it's lining a pencil and a phone along the barrier until they are flush but they are straight enough for it to work) and the fact that waves travel in straight lines through a medium until they bounce off of something or change media and the latter isn't possible in this game. I mean, I may be buzzed, but when the same approach can one-shot 100% the last several levels in only a couple seconds no more than three times through, I must doubt it's a player error that is causing it.