1) This recreates the original Half-Life in its sequel's shinier engine, and it's been in development since dinosaurs roamed the Earth. Much more than a simple port, Black Mesa updates Valve's game with fancier assets, new voice acting, a reworked campaign and more.
In the early versions of HL1 Gordon Freeman had ponytail. Later it was removed.
Not everyone is happy about it.
2) Minerva: Metastasis
Adam Foster's Minerva comes close to the quality of Valve's own Half-Life 2 Episodes—in fact, Valve was so impressed Foster joined the company. It's a sizeable story, about the length of an official chapter, with considered level design and a high level of polish. You begin the game strapped to the underside of a helicopter, before being dropped on a mysterious island with a sinister secret.
4) Stanley Parable
This is the story of a man named Stanley. Or rather, it's the story of the story: a deviously clever, reactive adventure that second-guesses your every move. As Stanley—or, perhaps more accurately, as the player controlling Stanley—you're free to follow or ignore the various instructions the wonderful narrator bellows over you, resulting in a tangled, branching story that rewards your curiosity, imagination, and defiance.
5) Portal Stories: Mel
Portal Stories: Mel is a community made, free modification for Portal 2 based in the Portal universe. It tells the story of Mel, who meets a new personality core and faces an undiscovered threat to the Aperture facility.
For its stylization of 1950 and dark humour i give this game 10/10 .
6) Blue Shift
Blue Shift begins in a similar manner to Half-Life, as Barney Calhoun rides a train through the Black Mesa facility to reach his place of work. After reporting for duty, Calhoun is instructed to assist in maintenance on a malfunctioning elevator. As Calhoun finishes repairs, however, Freeman's experiment takes place and results in a "resonance cascade", causing massive damage to the facility and teleporting alien creatures into the base. The elevator is badly damaged and fails, sending Calhoun plummeting into the depths of Black Mesa.
7) Opposing Force
Half-Life: Opposing Force is a critically acclaimed expansion pack for Half-Life, developed by Gearbox Software and released by Valve Software on November 1, 1999. The expansion's single-player mode features the same setting as the original, with the twist that the player is cast not as Gordon Freeman, but as Corporal Adrian Shephard, a U.S. Marine. Shephard is sent into the Black Mesa Research Facility on an undisclosed mission, but things go wrong as he finds himself fighting for survival against government agents, Xen aliens and the mysterious Race X. A fan mod is currently in the works that will see the whole game remade in the Source engine currently titled Operation: Black Mesa. Also, an unofficial sequel is being developed by fans named Opposing Force 2.
New weapons , enemies and effects. 10/10. (Official DLC)
8 Research and Development
Thanks to its then-revolutionary ragdoll physics, a lot of time in Half-Life 2 was spent throwing chairs at NPCs, or flinging teacups with the gravity gun. In that spirit, Research and Development does away with offensive weapons altogether, leaving just a couple of secondary tools to let you manipulate gravity or order Antlions about. Puzzles are the order of the day here, and it's surprising just how easily Half-Life 2's toolset translates to this new focus.
9) Mission Imporable
Your mission, should you choose to accept it, is to step into the sneakers of Gordon Freeman and set off to repair a Resistance listening post. This impressive Episode Two mod begins with Gordon rowing to a distant coastline: a coastline that reminds you just how pretty the venerable Source engine can look in the right hands. The right hands in this instance are a couple of established game devs, and their experience shines through pretty much every crevice of this slick, well-paced adventure.
You can meet Stephen Hawking