Just found this other adventure game A Second Face. Enjoy.

A very simple game I've played for dozens of hours in my black and white 1st generation Palm handheld PC was Space Trader. Somebody ported it to Windows, and now only that version exists since the original developer seems to have gone out of business (though it's easy to find the handheld game with some googling).
You start out with a small ship and travel through space buying stuff cheap and selling it expensive, until you get rich and can take a better ship. There's also some cool side quests. It's inspired in the old DOS game "Elite", though with no 3D. It's very addictive.
The Windows version is very faithful to the original, but I don't like it as much because it looks dated that way. You more or less expect a handheld game to look bad, but not a Windows game. I strongly recommend the handheld version for those rainy days on a bus. The Windows version should be just as good but I don't play it.
Another game that was actually a shareware demo but I played it like there was no tomorrow was Castle of the winds (first chapter). It's gotta have been the best game ever made for Windows 3.x, and I don't even like rogue-likes much. I *think* both chapters were released as freeware now, but I could only beat the first (it took me a few weeks already, but then I was 12).
Edit: I'm favoritizing this thread, lots of good stuff here.

Yup, Sadasoft released them for free according to this.
As rougelikes go, it's fairly simple. But I credit it as the game that got me into such genre after picking it up at a newsagent as a early teenager.

You can try Outspark's games. They are free and addictive games, I like Project Powder. It's a snowboarding game and better than Ubisoft's high budget title Shaun White Snowboarding.
http://www.outspark.com

As far as I can remember all games on Abandonia Reloaded are freeware, most of them being indie titles.

I always thought those games weren't officialy released as freeware. I've seen them as old games no one bothered about anymore because most of those companies are either no longer in existence or they have been eaten up EA style and maybe the big corporation doesn't even know what the hell it has.

AGDInteractive has released King's Quest I: Quest for the Crown V. 4.0 Enhanced Edition

www.teeworlds.com
/so/ much fun :)

Judas, you are getting mixed up with Abandonia.
Abadonia deals with abandonware - games that are now abandones. But Reloaded deals with freeware - games made by independant makers and are free. I'm very much involved with that site, so I can vouch for them.

Maybe it's just me then, but I swear most of those kind of sites aren't viewed as legitimate. And sometimes it's difficult to tell whether they are legitimate or not. Thanks for the information.

Reloaded contains nothing but freeware, so we are completely legit.
Have a look for yourself - http://www.reloaded.org/
( :

I think being "legit" or not is not even in the scope of Reloaded specifically (although being a relative to Abandonia they certainly have this strict off-limits enforcement policy), but their point is to present only freeware, so it's nothing to do with "abandonware". Most games are independent, including some mentioned in this thread.

So, who's played the Barn Runner games?
Brilliant adventure games about a cop that does as little work as possible. Really funny. ( :

Ahem, 3000AD's games. Battlecruiser 3000AD v1.0 and 2.09, Battlecruiser Melenium and now Universal Combat. Nothing better. NOTHING!