A free to play version of muliplayer-only shooter Gotham City Imposters hit the Steam store yesterday along with more than 50 assorted packs.

A free-to-play version of muliplayer-only shooter Gotham City Imposters hit the Steam store yesterday along with more than 50 assorted upgrade packs.

The Monolith Productions game pits vigilantes dressed like Batman against criminals dressed like the Joker in constant gadget-laden first-person-shooter online matches. The game includes 1,000 levels of player advancement and oodles of upgrades and unlocks, according to the game's official description on Steam.

The packs available for the game currently run from just under $1 to just under $5 and include weapons, support items, and costumes.