This mod implements 3 new weapons (BuilderGun, GravityGun and PortalGun) and more to Serious Sam - The Second Encounter. With Builder Gun you can push/pull enemies/players, copy and transport enemies and models (SP only), stretch enemies/models, instantly kill or spawn enemies. Gravity Gun works like in HL2 and Portal Gun spawns portals almost like in Valve's Portal. The mod also has 2 new gamemodes and 16-players multiplayer.
Screenshot from Puzzle Level 01