Tonight's game on OpenPOWER: ZGloom

We've done some DOS games recently, so for a change of pace let's do an Amiga one. Gloom was a pretty unabashed Doom knockoff using an Wolfenstein-type engine with some map geometry enhancements and transparency and palette effects. I actually have it on my A4000T and it's a bit blocky but plays pretty well with AGA and an '060. You know the drill: marine type guy shoots up other malicious marines, and, um, skinheads, and robots, and then ends up in a Gothic tomb as you do besieged by monsters and ghosts, and then goes to hell, takes the fight to the demons and kills a big dragon to save civilization. Just another day at the office! Its creators made it freely distributable and open-sourced the engine, allowing reimplementations to be made; probably the most developed of these is ZGloom. ZGloom isn't a perfect port — it's missing the title screens, the font and HUD are different, and there are various bugs ranging from trivial to moderate — but it has all the interstitials for what little story there is, has music and sound effects, plays well and does so at high resolution, and has configurable controls with X-axis mouselook. Also, because it's software-rendered, OpenPOWER systems with just the BMC framebuffer can play just fine (it has a multithreaded renderer to take advantage of all those shiny cores we've got). There's no save feature, but ZGloom simply gives you infinite lives, so just keep grinding away with impunity — and while you only have one weapon at a time, you can power it up, so grab all the bouncing orbs you can get for a real supercharge. Doors and switches are triggered by just walking into them, and baby bottles (!) give you health. There are other useful powerups you can find ...

I should also note for the squeamish that Gloom infamously came in "Messy" (temporary gibs) and "Meaty" (permanent gibs) modes, and this port seems to entirely play in "Meaty" mode, which means enemies explode and litter the ground with an alarmingly fast accumulation of body parts. On the original Amiga this would have brought lower-specced systems to their 16-bit knees, but this is a POWER9, so we can have all the fragmented torsos we want. (I have intentionally not shown this in the screenshot.) Don't say I didn't warn you.

Building it from source is straightforward; Fedora 36 has SDL2, SDL2_mixer and libxmp. Before you type make (or make -j24), however, edit the Makefile and add -O3 -mcpu=power9 to the CXXFLAGS. Then download this ZIP of the game resources, unzip it, and copy or symlink the ZGloom binary inside the resulting directory. While you can jump to any level from the main menu, game settings (graphics, keys, etc.) are controlled from the in-game menu after you actually start one.

Now things get serious!