Very nice puzzle game.
Starting from level 3, I had troubles to find correct solution, but eventually made it all the way to the end level.
The idea is great and finding the ballance between budget and signal power was challanging. I liked the limitation on number of towers placed - at firt it seemed like an restriction, but at the end it was rather helpful hint on what towers to build.
Level design seems to be well thought. I felt like there is not many different solutions (but at the same time I am sure there is) which made me feel proud to find one that function at the end.
Visuals are simple, but works well with the game - the blueprint theme is clever way how to make much from less.
Great job!