У вашего броузера проблема в совместимости с HTML5
Today, I play Gmod and view some mods from the hit game by Valve, Portal.
Portal Gun: http://steamcommunity.com/sharedfiles/filedetails/?id=336509414&searchtext=portal+gun
Wheatley: http://steamcommunity.com/sharedfiles/filedetails/?id=109221398&searchtext=portal
Rick: http://steamcommunity.com/sharedfiles/filedetails/?id=117711571&searchtext=portal
Space Core: http://steamcommunity.com/sharedfiles/filedetails/?id=109224143&searchtext=portal
Turrets: http://steamcommunity.com/sharedfiles/filedetails/?id=123279188&searchtext=portal
Chell (included with Gmod): http://store.steampowered.com/app/4000