Yes. It runs in your browser, with nothing to install and no account.

No. Only the engine is a PHP port of the source code released under the GPL. The name, the monsters, the weapons, the levels, the graphics and the sounds are original, and no file of the original game is used.

To show that a language people think of as a web language can run a real software 3D engine, at 60 frames a second in the browser.

The code is free software, under the GNU GPL v2. You can browse the sources on the project page.

IRON ABYSS – retro FPS in PHP, play free online

The game

Mining station 7. The machines dug too deep, and whatever they woke up has taken over the droids.

You fight through three levels: HANGAR 7, PROCESSING PLANT and THE CORE. Find the keycards, ride the lifts, avoid the acid and the lava, find the secrets and take down the Warden that guards the core.

Screenshots

IRON ABYSS – PROCESSING PLANT — PROCESSING PLANT

The engine

The engine is a PHP port of the software renderer and game logic of the 1993 engine, whose C source was released under the GNU GPL. It has the BSP walk, walls drawn column by column, floors and ceilings as visplanes, colormap lighting, 8-angle sprites, 35 tics a second and the monster AI.

The same PHP code runs on the desktop and in the browser, compiled to WebAssembly with JumPHP. Every frame, PHP computes a 320 × 168 picture, then WebGL puts it on the screen.

All the content is original and made by code: the textures, the sky, the monsters (modelled in 3D, then photographed from 8 angles), the weapons and the sounds.

Monsters and weapons

Husk: a hijacked drilling droid that fires bursts.
Gnasher: a fast beast that bites up close.
Spitter: claws up close, acid balls from afar.
Warden: the armoured guardian of the core, with a plasma cannon.

Wrench, sidearm, scattergun, riveter and ion launcher.

Levels

HANGAR 7: hangar, open-air courtyard, computer room, red keycard.
PROCESSING PLANT: acid channels, storage, a yard with stairs, blue and yellow keycards.
THE CORE: lava cavern, antechamber, the Warden's arena.

Controls

Arrows / W S	move, turn
A D	strafe
Shift	run
Ctrl / F / click	fire
Space / E	open, use
1 to 5	weapons
Tab	map
Escape	menu
Gamepad	stick, RT fire, A use
Phone	touch stick and FIRE / USE buttons

▶ PLAY NOW

Questions

Is it free?: Yes. It runs in your browser, with nothing to install and no account.
Is it the 1993 game?: No. Only the engine is a PHP port of the source code released under the GPL. The name, the monsters, the weapons, the levels, the graphics and the sounds are original, and no file of the original game is used.
Why PHP?: To show that a language people think of as a web language can run a real software 3D engine, at 60 frames a second in the browser.
Where is the code?: The code is free software, under the GNU GPL v2. You can browse the sources on the project page.

Credits

Engine ported to PHP from the source code of the 1993 engine released by id Software under the GNU GPL. JumPHP framework. Original content.