[dvh]

Isn't it just bi-copter?

[daww]

You are technically correct - the best kind of correct. But yeah, think of it as a "slice" of a quadcopter along one of its principal axes. Writing the 3D blog post right now.

[palata]

No, it's a quadcopter setup, but simulated in a 2D world (I guess for simplicity). A bi-copter would require tiltrotors, which is different.

[echoangle]

In 2D, a bi-rotor is equivalent to the quadcopter in the post. There are 2 thrusts you control to guide the thing.