Tremulous is a free, open source game that blends a team based FPS with
elements of an RTS. Players can choose from 2 unique races, aliens and humans.
Players on both teams are able to build working structures in-game like an
RTS. These structures provide many functions, the most important being
spawning. The designated builders must ensure there are spawn structures or
other players will not be able to rejoin the game after death. Other
structures provide automated base defense (to some degree), healing functions
and much more...
Player advancement is different depending on which team you are on. As a
human, players are rewarded with credits for each alien kill. These credits
may be used to purchase new weapons and upgrades from the "Armoury". The alien
team advances quite differently. Upon killing a human foe, the alien is able
to evolve into a new class. The more kills gained the more powerful the
The overall objective behind Tremulous is to eliminate the opposing team. This
is achieved by not only killing the opposing players but also removing their
ability to respawn by destroying their spawn structures.