The game could be prettier (and for that reason probably won't get the rating it deserves), but the concept and the execution are excellent imo. I like it a lot.
Not as good armor picross, sorry.
The one feature I'm really missing is that the puzzle automtically detects when a row/column is "finished" so I don't have to count the fields every time. That's sometimes tedious on bigger puzzles.
I like the game, but it doesn't have much depth I'm afraid. Maybe writing some kind of storyline to tie the missions together would be helpful.
And the balancing isn't that good either compared to other tower defence games - it's a struggle in the beginning, and once you've set up your towers it's just click automatic waves and double speed and wait for it the end the last couple dozen waves.
Still 4/5 though imo.
I like the game, but I think the accuracy of the pinpointing is slightly off. After playing a few times I've hit 0km several times, but never anything between 1 and 40 - I think it's highly unlikely that that's correct.