OpenTTD is open source, so not sure that fits.
Older? Check.
Free? Check.
Software/game? Check.Checks out in my book!
I happened upon the original for $20 in Wal Mart in 1995 and I’ve been playing it on and off ever since!
One of the best games ever made.
I don’t know if it technically counts as freeware, but Space Cadet Pinball. Back on XP it was my go-to for something quick to play on the offline computer, and I just brought it with me to every new machine. Also it’s now been decompiled and will run on pretty much anything!
The powder toy. It’s a physics simulator. I fire it up during meetings
I’ve been playing it off and on since maybe 2016-18 (somewhere within that range), so a pretty long time for me, but Pokemon Rejuvenation.
If you don’t mind swearing, death, and generally kinda edgy stuff, it’s a fun enough game with a lot of content. 15 out of 18 badges (one per type) are currently available, with a very long story to go with it.
Just started over on my Steam Deck, making this my umpteenth time starting over, because I felt like it and wanted to do a grass only run, similar to my fire only run. Also, unlike just about every other RPGMaker XP fangame, the devs have a Linux version available, which has an appimage instead of the .exe file to run the game and have made a bash script to update the game to replace the .exe file for that. Wine not required to play at all!
Haven’t played recently, but this one came to mind’
I missed the original, but Scorched 3D was a big hit at my high school.
Beneath A Steel Sky (though I kinda prefer the grungier aesthetic of the Amiga floppy version)
Available free on ScummVM!
Has an excellent plot and wry sense of humour. Fun game.
OpenTTD
If we’re sticking strictly to free, I’m not sure Doom mods work if you only have the free version installed. Either way, people basically never stopped making wads since the game came out, and I try various ones out from time to time.
There are tons of them, so if you’re interested you can see what won the annual Cacowards throughout the years and start there.
One of my absolute favorites is a quirky strategy game named Lord Monarch. I found it on the Nihon Falcom website way back in the mid 90s when I was first starting to use the internet: Lord Monarch
It’s super tiny in modern terms, but I remember waiting a good 20-30 minutes for it to download from a 33.6Kbps modem.
Another huge one for me was a game I actually got a full version of from a Gravis gamepad promo CD named Seek and Destroy. It’s a top down shooter where you can be either a helicopter or a tank: Seek and Destroy
The last one that comes to mind is a giant robot fighting game that also came on that same Gravis CD named One Must Fall: One Must Fall 2097
bubble tanks
UnReal World is a free, survival-focused roguelike rpg that came out in 1992 and is still actively being developed and improved. It’s got a lot of depth and a very cool fantasy setting heavily inspired by Finnish folklore (the developer is Finnish).
I highly recommend it if you’ve got the patience for an in-depth roguelike rpg.
Lost Vikings
Super Crate Box. An incredibly addictive, simple 2D shooting game! It’s free on Steam!
Irisu Syndrome! is a favorite of mine. It’s only from 2008, so I personally don’t consider it retro. It’s tricky to learn at first since it doesn’t tell you anything about how to play and I don’t recall there being a manual. It’s also one of those games that you can’t really say too much about without spoiling things.
SRB2 !
Sonic Robo Blast 2 is one of the best Sonic games ever!
Man, I found this in 09 a few months before the 2.0 update. And it had a decade behind it even then. Man I miss those days of looking through random wads on 4shared. I couldn’t even begin to figure out how to find some of that stuff nowadays if I wanted to find it.
