The differences in terrain are very, very good. Indonesia has dense jungle , with rugged terrain, while Uzbekistan has bleak and barren landscapes with towering peaks. All the terrain I saw was nicely implemented. While I have not been to Uzbekistan, I can surely imagine that it looks similar to how it's protrayed in the game. The Multiplayer option consists of connections to Novalogic 's Novaworld, LAN, IPX, and Modem.
Missions are very similar to all the other action shooters out there.
The Novaworld server also has links to password games and public player-created games not created by their servers. I found this to be a welcome addition, since most of the Novaworld server games were some type of Deathmatch. Those games get a little old after a while, and it was refreshing to find people willing to host and play Coop and other Team games. In Multiplayer, the host sets the general preferences and then allows other players to join him or her in the game. This can be partially explained away by the mission length, which can be quite long for some locations.