An awesome local COOP game with a 90% rating on Steamdb and "Very positive" on steam.

Description:
PARTICLE MACE is a game inspired by Geometry Wars, Asteroids, Amplitude and many others. Unlike in traditional twin stick shooters, in Particle Mace, you destroy your enemies by swinging giant boulders at your enemies. It takes a deep understanding of your own weight, thrust, and inertia in order to be a master Particle Mace gladiator, but once you get in the zone, this game satisfies like no other.