Multiplayer
This was a little harder to judge, given the limited number of servers I pinged, no doubt due to the fact that the retail version was just released. I was able to play the demo quite a bit online and found that the Capture The Flag and Deathmatch games played exactly like you would expect. There are quite a number of fixes in an upcoming patch, mostly related to multiplayer. Perhaps we will revisit it in greater detail at that point.
I did get a chance to play through each of the multiplayer levels on my own (curiously, despite the Unreal Engine having excellent bot support there are no bots in the game) and can say that each are unique and well-suited to the gameplay that Devastation is geared towards. The included deathmatch maps consist of a couple of dilapidated parking garages (complete with destructable cars!), a sharp looking "circus" map, a sewer, a creepy mental hospital, a cityscape, and a rooftop snipe-fest.
The Capture the Flag levels include a trainyard (in demo), and a great Chinatown map called CTF-Chozo. Both maps are quite large, especially the latter. It would have been nice to see more maps for this gametype.
The new gametype, Territories is a team-based game in which each team attempts to gain the code to the opponent's base, where the defenses and respawning devices must be destroyed. After this, each enemy must be hunted down and killed. Many of the maps from the Capture the Flag and Deathmatch gametypes are reused here, adding a subway map and another rooftop map.
It's worth noting that a Devastation specific copy of the Unreal Editor is included with the retail game. It's widely known that this is one of the most powerful, flexible, and easy to use 3D level editors around. That is to say, there's no doubt the game will receive mapping support from the Devastation community. That's great news because, while Digitalo have generously provided a number of multiplayer levels along with their singleplayer game, there no doubt will be many more available soon.