Is the absence of any notable Half-Life release like ants under your skin? Allow Prospekt (opens in new tab), Valve-approved sequel to Gearbox's Half-Life: Opposing Force, to ease the long withdrawal. It's out today (opens in new tab), priced £7.50/$10.
Perhaps you thought Freeman's run of good luck in fighting the Combine was a product of your own prodigious skill and a little intervention from the G-Man. You would be mistaken. Prospekt picks up as Freeman is marauding his way through Nova Prospekt prison. To keep the odds in his favour, the Vortigaunts teleport US Marine Adrian Shephard—you—into the fray.
Developer Richard Seabrook has been beavering away on Prospekt for two years, and claims it rivals Half-Life 2: Episode One (opens in new tab) for length. It's a standalone, so you won't need Half-Life 2 to play it, but of course that won't matter because you have it anyway. Assets from existing settings have been upgraded as befits a modern game and, most interesting, we're promised a return to the alien plane of Xen (opens in new tab).