Wow, is that City 17?, they used HL2 sounds,
the video is something else, better than the DOOM movie fps scene
The orange box contence:-
half-life 2 / half-life 2 episode 1 / hlaf-life 2 episode 2 (the half-life 2 collection to date taking you through city 17 to the outskirts of the city into rural areas when you sign up to steam with this you can download half-life 2 lost coast for free any many other mods.Portal: A problem solving game with the use of a portal gun which when fired creates an entry portal and fired again creates an exit portal. (these files can be taken out of the game and placed in the half - life 2 game for a bit of fun teleporting behind your enermy.
Team fortress 2: A multiplayer based game with some wacky weapons also you can go in invisible mod on this for a limited time which isd fun.
when i placed the orange box on steam i also download garrys mod its around £5 and all the maps used in the orange box can be used on garrys mod which is like a sandbox mod but u can do more make anything and i mean anything. There are also alot of free mods you can download which are good fun there is one called insurgency which is alot like cod4. If you like modern warfare for mohaa then you would have to get counter strike source which is only a few quid aswell. enjoy