While you can still download the original demo (and Day One also), it does have some issues running on modern systems, just like the WON version of Half-Life (which is why Valve should fix Blue Shift and the HD Pack already, so I don’t have to juggle WON and Steam, and some unofficial mods around whenever I want to play).
Which is just why several modders have made several versions of the 1999 classic.
SteamLink by Ryan Finnie
SteamLink is a version of Uplink designed specifically to work with Steam. It contains all the original files, no HL files are modified in any way, and it features some nostalgic loading and menu screens.
It’s compatible with PHL’s fixed HD Pack (which has a no-tongue Barney, thus proving Murphy’s Law, again), and I strongly recommend it.
Uplink Lite by Jason Stephens
Uplink Lite is a bit more interesting. It’s an attempt at making an easy to download, install and use package of Uplink, that can be easily mounted on the retail game. It only includes the maps themselves and some other files. A retail version of HL is required, and installation is easy. It should work on Steam, but I haven’t tested it. Check it out if you ever need to access Uplink in a hurry, from HL1 itself.
There’s also a version of it called “Uplink Lite Plus”. I have no idea what it is, but I’ve put the DL link in there as well.
Uplink Addon by Werner Spahl
Uplink Addon is even more interesting.
Rather than turn Uplink into a HL mod, or a series of HL maps, it puts Uplink in the game itself, seamlessly.
Sadly, the nighttime period does mess around with HL1′s continuity.
Uplink Addon also adds a few other things to the game itself. I’ll leave them as surprises.
Definitely check this out. May have problems with Steam, but DEFINITELY worth your time.
I saved the best for last!
Uplink Extended is a remake of the original. It looks at the original maps and fixes some mapping errors and inconsistencies, and it extends the ending. I won’t spoil that either.
It works on Steam, so check it out immediately, cause this is amazing!
And that’s about all of em. Hope you enjoy them, folks!