That's a nice and funny game, I love it. It's smooth and beautiful (1920x1080-Fantastic on Ubuntu 20.04). VFX-sound is funny as well, many ways to achieve the goal, very friendly for non hardcore gamer like me. Towers are amazing with their different rates.
My best score is 253 rebels remaining at 100% with only 3 buildings (tower on the right was the only one to be upgraded)
Walk-through: 1) build the top one near the exit and wait 2 waves.
2) when second wave is finished build the bottom one.
3) when you have enough money build the right-side building at 23 rebels (faster pulses)
4) then wait the end of the fifth wave to upgrade that last tower to 60 rebels
6) then enjoy accumulating rebels while at 100%