Top similar games like Operation: Black Mesa:

MUTATION PHASE is a horror-shooter with a first-person view, which narrates the consequences of experiments with sound waves. You have to survive among hordes of mutants and get out of the danger zone.

Multiplayer FPS Game in the style of old-school browser shooters set up in the fictional Cold War battlefields! The game feature fast-paced FPS gameplay with online players or AI BOTs, a huge variety of weapons, unique maps, the progression system, and many more features!

In this game you have to fight your way through hordes of zombies in search of a safe place.

Only Lead Can Stop Them is a retro FPS set in the Spanish Civil War. Fight the Fascist Hordes!

Once again, you are on board Shakhter-One. Traverse the deck of a well-known mining ship and the depths of Mark's twisted mind blended together. Run, fight, hide, explore – discover, what really happened to this place and do your best to destroy Shakhter-One.

Sabotage a cult and their schemes in this Mystery, Horror, FPS. Explore a mansion while massacring the creepy followers and their foul abominations. Find various weapons to slay your enemies with and uncover the cruel secrets of the organization.

In a galaxy far away a world is facing doomsday. As nations rise against each other the world is plunged into chaos. Many illegal groups such as gangs and independent militias and demonic cults take the advantage of the situation to expand. Your task is to assassinate a demon dubbed Lord of Terror.

Something is happening in town. People are going crazy attacking each other. Can you survive to find out what's causing this insanity? Who's behind this zombie outbreak?

You are a TEC Engineer from Earth ordered to retrieve and return sensitive data from the TEC Mining Facility on Titan. On arrival, you discover that the facility has been invaded by beings from another realm. Contend with these abominations as you complete your mission and escape Titan.

"Silence In The Cabin" is an Open Map Survival Horror Game, where you must survive Dark linear story sections in order to unlock more areas of the world.

A thrilling, first-person, action-survival game set in the modern post-apocalypse. As mankind’s last hope, you’ll traverse the hospital ravaged by a lethal plague. the fight for survival gets progressively more difficult as the story unfolds. Be ready for violence

Perilous Warp is a fast-paced indie retro-shooter inspired by the classic 3D-actions. Communication with a distant space colony has been lost, and you bravely step into the teleporter with the desire for glorious adventures. But do not expect to win in a heartbeat!

Boomer shooter about a robot obliterating aliens.

Death is only the beginning. Crawl from your grave and gear up to fight your way through the ranks of a mysterious and twisted cult. You, your guns, and your dynamite will have to shoot, slide, blast, duck, dodge, and maybe throw a gib or two to survive in this old-school-inspired shooter.

Embark on a thrilling journey through the eyes of a security gate officer who must face super-biological horrors beyond both knowledge and comprehension in this first-person shooter styled after old PS2 game graphics.

Explore the gloomy rooms of a sci-fi base as a doomed marine, the sole survivor of the portal experiment. Save humanity as you did in the 90s with your trusty shotgun, make your way through ominous corridors inhabited by the shadows of sinners and evil spirits.

Fight for survival in the Backrooms. Play with friends in multiplayer or solo against AI bots. Unearth the terrifying monster scorestreak and get ready for an intense experience!

Relive Half-Life.

Enter a realm of nightmares and claw and shoot your way through hordes of bloodthirsty vermin and things that are much, much worse in this retro FPS

Witching Hour is a zombie wave shooter where you have to survive until the clock strikes 12. You are trapped inside the house while hordes of zombies attack you from every angle. Can YOU survive until witching hour?

You are following the story of security guard working at power plant which uses experimental technology, designed to draw electricity from atmosphere. One day you start hearing strange stories about anomaly sightings, soon you witness something terrifying and start experiencing nightmares...

Blood Rot: 1918 has players fighting against hordes of the undead in the midst of The Great War. Survive solo, or with friends in this first-person zombie shooter.

Cybershow is a fast-paced first-person sci-fi action shooter. Battle your way out of the city against the local military and police!

Splatter is a first-person fever dream where you blast constantly-adapting enemies into neon sprays of pulp and slime. Enter a digital mindscape constructed by four anonymous administrators. Can you survive? Can you remain sane? Can you remain yourself?

STAND YOUR GROUND is an immersive tactical FPS game where you must defend yourself from armed attackers. Play as an American Civilian, who is well within their right to legally own and use a firearm, and fight your way out of situations inspired by actual events - or let the attackers take over.

Coven is a hyper violent, retro fps which is heavily inspired by classic fps games such as Blood, Hexen and Timesplitters. Destroy your enemies and eat their flesh.

Put on your armor, choose a rifle or a shotgun - now you are part of a special forces group. Shoot your way out of a skyscraper full of zombies.

A free to play multiplayer survival horror game with a unique damage system. One bullet can be game over if not treated properly, and you must be willing to lose an arm and a leg to finish your objective.

A first-person fight to the death in the depths of space!

A horror survival game that unfolds in an ancient district of Jeddah, Follow the protagonist as they uncover the mystery of BREEKHA Hospital, where bodies disappear only to return to life in a grotesque and unnatural manner.

Fluffy Bastards is a FPS in a grotesque fantasy world where you play as Theodore, a humble gamekeeper. The goal of the game is to destroy all rabbits that stand in your way and save the world. Do quests, get the best weapons, and find out how to stop the invasion of bloodthirsty rabbits! Damn you!