Level cap was removed in v1.1 a day or two ago, with levels past 24 requiring 1 million more points. I really like how the developer actually listened to all the complaints and changed things.
My crossfire tactic: 20 energy, 8 stability, 1 projectile, 25 manipulator, 6 shockwave
Just blast those purples at everything, making sure the nuke trucks don't get too close to you.
And for the end of level 23, it helps to have the manipulator/shockwave/implosion. Preferably 2 or more. The manipulator and the shockwave have gotten me out of a lot of sticky situations.