Counter Strike Online is developed by Korean game developer NEXON with oversight by Valve, and published by IAH Games as a free-to-play game. In CSO, Nexon changed very little from the basic formula that made CS popular.
But by far the most exciting content new to CSO would be the addition of three new game modes: deathmatch, team deathmatch and zombie mode. In the deathmatch modes, you spawn within seconds, ready to go again, instead of having to wait for the beginning of a new round before spawning again. You are also given a few seconds of invulnerability to prevent you from being killed before you can reorient yourself to your surroundings.
The deathmatch modes are a boon to those players who like an endless stream of action – especially when combined with the sniper rifles or AWP only modes. It’s pretty obvious how popular these modes are, since the deathmatch and team deathmatch modes appear to be the most played modes so far in CSO, with at least two to three games of 24 players each going on at most hours.
What’s interesting though is the completely new zombie mode. In this mode, a random player is selected to become a zombie. Zombies have an enormous amount of health and speed, and are able to kill human players in one hit. The twist is that as the humans get killed, they too become zombies.Zombie mode games are very frantic, with the humans trying to hide behind natural chokepoints to prevent zombies from getting to them, or just trying to outrun zombies. As you can imagine, zombies win most of the time. One problem of the zombie mode is that, more often than not, it degenerates into human players attempting to use map exploits to reach areas of the map where zombies find it hard to reach. It’s still good fun though – just don’t expect a very balanced gameplay from this.