There is a constant flow of enemies defining an ever changing battle line. Work with your team to push the battle line deeper in to enemy territory. Disable all the enemy Spawns to win. You will be paid for any dead enemies. Use this money to buy weapons and friendly spawns.
Template map to allow you to make your own swarm map. It has all the entities set up. Includes a read me to explain a little about how to use the map. Post any questions on the site and I will try to explain more about the entities.
How do you make levels for Swarm?
With the Hammer Editor in the Source SDK. If you want to make a level you will need to have a basic understanding of how the Hammer Editor works.
Hey, it works n' all. But it'd be great if you could make an .fgd for swarm, so that triggers and things work. ^-^
Nevermind, I managed to make it work.