Thanks! I love Mindustry too! But I didn't even realized I took it as inspiration :P
I tried to make the level progression go slow, so that the level don't get too hard too fast, but I could certainly fit some more levels in there to make it even smoother. It does ramp up dramatically after level 8 or so.
I do plan on adding more mechanics, like colors and new machines, so I think that would also help make it feel like the levels ramp up more progressively, maybe :P
Anyway, thanks for playing :D