It's about 2000 EXP for every 10 sec your life. GL
On this map, you can both make achievements related to killing monsters, and just gain experience.About 2000EXP for 1 run.
Put the map in steamapps\common\Alien Swarm\swarm\maps\
Type 'map EXPF' in the consol.
Choose any Marines and his equipment.
Start the game.
To exit the map (successfully complete the mission) and gain experience, go to the upper right corner. (marked with yellow lines on the floor)
