You drag left and right to guide a crowd of little shooters down a lane, and they shoot on their own, constantly. Break the towers ahead and the riders on top drop down and run to join you.

Steer onto the people scattered along the ground and they fall in behind. Your shooters carry numbers and merge into heavier ones as the crowd grows, so a big crowd is worth far more than the sum of its people.

The decision the game is built around is what your firepower is worth spending on. Gates stand in your path with a number on them, and shooting a gate makes that number climb — run through and you collect whatever you charged it to.

But every bullet you put into a gate is a bullet that never reached the tower behind it, and a gate you ignore stays in the red and takes people off you instead. There is no right answer, only the one you can afford.

Crossing the finish line is not the end of it. The horde comes at you, and every attacker that reaches your crowd kills a shooter and cuts your damage with them, so a run you scraped through can still fall apart at the last.

Win and you land in a new world — Lagoon, Sunset, Deep, Jade and on — with your winnings and a clean slate, each one its own build-up rather than one endless ramp. Every run pays whether you win or wipe, that cash buys fire rate and start power, and the first wipe of any run is free.