Able to play, however mouse travels outside of the game window. (I use a triple monitor setup. "Xinerama" disabled in NVIDIA X Server Settings during testing).
You can try to simulate desktop for this particular wineprefix and restrict cursor to the fullscreen windows via settings. Should do the trick.
proton 3.7-4x1 2018-08
Observed: Game refuses to launch normally as BattleEye either fails to start correctly or crashes.
Game complains about invalid registry key yet runs regardless. Game can be run without BattleEye via launch options and graphics/sound are fine in single player campaigns. Able to play, however mouse travels outside of the game window. (I use a triple monitor setup. "Xinerama" disabled in NVIDIA X Server Settings during testing).
Game crashes when trying to access multiplayer online server list.
Steam Play: Proton 3.7-4 Beta
Description: Ubuntu 18.04.1 LTS
Release: 18.04
Codename: bionic
Kernel: 4.18.4-041804-generic #201808220230
Gist: https://gist.github.com/supashang/d096ee4b779570009e25a1076c63a4ed
System Info Gist: https://gist.github.com/supashang/6050de4e5ed8854f58d7152521048170
Intel Core i7 4790K @ 4.3GHz, ASUSTeK COMPUTER INC. Z97-PRO GAMER (SOCKET 1150), Corsair Vengeance Low Profile 16GB Dual-Channel DDR3, 4GB NVIDIA GeForce GTX 970 OC STRIX, Samsung SSD 840 & 850 EVO