Using VirtualBox (4.3.18_Gentoo) w/ Xubuntu 14.04 (3.16.0-34-generic
#45~14.04.1-Ubuntu SMP)

In "window" mode - no problems were observed in game play.
In "full screen" - cursor was uncontrollable with mouse but input to keys was
responsive.
Do not believe issue is related to VM. Will double check as well as verify with
git version.