This is the game's bread and butter. You can stack up to six weapons on top of each other, allowing you to fire shotguns, lasers, and rocket launchers simultaneously [2, 3].
The primary platform for the XXL edition. It often goes on sale and includes full Steam Workshop support and achievements [1, 2]. Download Serious SAM Double D XXL PC Game 2011
Another legitimate key provider that often supports charity with your purchase. Why Play XXL? This is the game's bread and butter