Based on Return to Castle Wolfenstein's engine, Enemy Territory started as an additional single-player campaign, but quickly evolved into a massive on-line shooter in minds of creators. The final product is a multiplayer-only, tactical and teamplay shooter. Pick your class (Soldier, medic, engineer, covert operations or field operations) and cover your teammates, heal them, build machinegun nests, bridges or deploy landmines, request airstrikes or artillery support, steal your enemy's uniform, and finally give your comrades ammo. In order to be successful, cooperative team playing is required.

Kissaki says

10/10 - Agree (6) Disagree

Wolfenstein: Enemy Territory is a free class-based team-play-oriented game with different objectives to reach on each map.
The objectives make it very unique and fun to play.

Game-play is fast (quake-style strafe-jumps etc.) but still demanding and fair when it comes to shooting (hit where you shoot, require at least 3 head-shots for a kill).

The modding community brought several mods and a huge number of maps for it, so much to check out if you’re looking for more content.

Although not as known for being an eSport game like others it is (or was) one of the most played games for a long time, also in eSport. The classes and unique objectives make a great base for stopwatch-mode matches where one team has to beat the time of the other team (sides switched).

The game was developed by Splash Damage.
Although planned as a selling-title it was released as a free, full version.
After support was dropped the community created own patches to fix issues and technically improve it further (Version 2.55, 2.60 and 2.60b).

Different mods allow for different game-play styles.
Etpro always had the best hitboxes and was rather constant in releases (not as many as fun-mods).
Other mods like NoQuarter and Etpub add fun-features like keeping experience and levels, unlocking new weapons and abilities.