Soldat (Score 5, Informative)

http://www.soldat.prv.pl/

Good fun, low system reqs and highly networkable 2D shooter!

From the site:

Soldat is a unique side-view multiplayer action game. It takes the best from games like Liero, Worms, Quake and Counter-Strike and gives you fast action gameplay with tons of blood and flesh. Soldiers fight against each other on 2D battle arenas using a deadly military arsenal. This is what multiplayer was invented for.

Most important features:

* Game environment based on real physics rules
* Over 18 weapons available:
- guns like MP5, Ak-74, M79, M249 Minimi, Barret M82A1, XM214 Minigun
* Multiplayer network game over the Internet or LAN
* Intelligent bots
* 6 game modes:
- Deathmatch
- Pointmatch
- Teammatch
- Rambomatch
- Capture the Flag
- Infiltration
* 35 different maps
* Editors: Soldat Map Maker and Interface Maker
* Lobby server and dedicated server for Windows and Linux