Thats Because u can't pass one mission doesn't mean that the game is buggy. Don't rush with your opinion that fast, before u are't shure u can't do it and i also bet that u don't even look the screens that the game is representing to you of how to: move, shoot, react etc. ...This game is buggy, very buggy. Now stuck at the crashed plane cockpit and cannot get pass the steel animal. Anyone here managed to get pass this stage?
W(press and hold)->Left Shift(press and hold)->Left Ctrl(press and hold)
You will slide into the tunnel.