Serious Sam 3 is a nice updated version especially with the mod community bringing a game that is already wacky WITH more wackiness. :D

This game is free. Don't knock it down for being low quality on graphics and such. Thinkn of Resident Evil. Not RE6 or 5. Think of more like RE1 with the open door and exploration of different enivronments in one giant world. The game has a lot of content. First off the campaign is awesome. The voice acting is very good. Now add in a another campaign after beaing the game, then add in a "survival mode" arena idea, add in co-op, add in extra content such as outfits, then add in a harder difficulty. Oh so much stuff! Its a very good game. Remember this is a Half Life 1 mod. Not 2. Its impressive. And avoid and ignore the harsh complaints on the game. Its terrifying. Sure some cheap scares are there, but the atmosphere is horrific. You never know who you might see around the corner. >:D

This is a very fun indie game. It is short but it is quite the $3 dollars.