I am interesting, after JMAC takes already 12 sessions playing Hadean Lands in youtube (2 hours each), and he still hasn’t finish the game, wich are the longest games ever.
I know some extra lenght lenght games, but not his lenght.
T-zero
Not a simple ballerina
Finding Martin
1893
One of my favorites of all time, and one I have actually asked around about on this forum because I was too intimidated to start at first: World - Details (ifdb.org)
An amazing Lovecraftian thriller where I was completely immersed in my character snooping around, to the point of closing doors and cabinets behind me lest some NPC would notice my activity: Lydia’s Heart - Details (ifdb.org)
Huge oldschool medieval fantasy quest: The Fortress of Fear - Details (ifdb.org)
Castle Ralf is really long… in fact, I don’t think anyone has ever finished it. I played it on and off for 6 months back in the 90s and didn’t finish. I’m going to pick it up again after I get my current game squared away.
Jason Dyer of “Renga in Blue” blog recently finished Time Zone for the Apple II (1982). His total playtime was 24 hours. If you read his blow-by-blow of the whole play, you can see how he spent those 24 hours!
For some context, an Apple II game was usually sold on one 140kb floppy disk. Time Zone came as six double-sided disks, or 12 floppies of 140kb size. You had to change disks and sides whenever the game asked. The six floppies thing was gobsmacking to a kid who was only aware of the game (e.g. me).
Renga in Blue is one of the more prolific blogs appearing on Planet IF. I visit Planet IF once a day.
-Wade
I guess there is a difference between the longest game to “solve” and the longest game to “play to completion”.
If you’re looking for the longest game to “play to completion” then I guess you could use published solutions and count the number of turns it takes. Certainly, there were many “long” old-school text adventures that took a long time to play simply because of the time it took to navigate the (mostly empty) maps. (Many multi-part, three; four; five; six instalment, adventures too.)
(And another +1 to the suggestion to read Jason’s blog too. Anyone remotely interested in where the genre started off should find it fascinating. There are some really interesting early games.)
I take note of Renga in Blue, but I dislike info sites where you finally can’t find a link after reading an interesting text wall…
I’m pretty sure longest game to solve isn’t the one meant. I have dozens of unfinished games…
Has anyone here managed to “solve” glkchess at level 8? I stopped at 5.
The example given in the OP referred to a playtime on a YouTube. So it really depends if the videos were of someone playing through and solving the game from scratch, or of someone playing through the games following a solution/knowing what they were doing.
A playtime of 24 hours very much sounds like someone playing through and solving the games as they go. I’d imagine that most single-part adventures have a playtime, following a solution, of between twenty minutes to two hours.
Roberta Williams regularly spent a week for each playtesting TimeZone session. So, it depends on the game.
I think Zork series has 40 hours expected playtime each? I could be wrong. I never finished any of it.
Pehaps, but if you’re following a solution then Zork I and II are about half an hour each. (See videos on YouTube).
So, again, it’s a case of defining what “long” means. Some of those “long” games are only “long” because they’re complicated to solve or the maps are huge. With a solution, they’re not particularly long at all.
Small, difficult games can be “longer” than massive simple ones. “Time to beat” is hard to assess and standardise.
Number of turns to get 100% would seem, to me, to be a potentially measurable way of judging a game’s minimum length.
Puzzle count is more interesting to me as a metric.
A badly designed puzzle could take weeks to solve potentially, if ever.
How about mandatory vs optional puzzles? I find that lately, I keep designing everything as optional puzzles(1), and that you can finish the game solving minimal number of puzzles, with corresponding low score.(2) Should such games be considered solved? How high of a score should you get before you solve the game?
Or … “This game is too easy! All you have to do is type WIN GAME, and you win! With score of 0, but still…” (3)
(1) by keeping the harder puzzles as optional, players can still enjoy the game even if their puzzle solving skill is still undeveloped. IMHO, good invitation for new players.
(2) That means unsolved puzzles can be mistaken as red herrings. But I won’t get into that on this thread.
(3) Another entry of silly command you put in parser game. 
To go back to the original example: I think Hadean Lands usually runs about six to eight hours if you’re not reading all the text out loud on a stream.
I usually, recently do some game betatest. I am trying to control playtest time to feedback how the game can take.
Second, third…tenth try I go looking for usability, not workability and can take much less than a quarter time of the first gameplay.
Cragne Manor is long - it has contributions by 84(?) authors who each made one room, and many of the individual rooms contain an entire mini-adventure.
Blue Lacuna “runs to some 365,000 words (not counting comments or the Standard Rules), about five megabytes of uncompressed text.”
Tin Star is from Choice of Games: “A single playthrough from beginning to epilogue can run over 80,000 words. The source code for the game is over 1.3 million words long.”
Choice of Robots, also by CoG: “an epic 300,000-word interactive sci-fi novel”
Hi everyone! We’re mentioning Time Zone, but by far the longest game I’ve done so far in terms of raw playtime was Warp. It was probably around triple the time it took me to beat Time Zone.
In order to play WARP, Adventure, Mystery Mansion or Trek 73 you have to download hp3000_adv_warp and extract to a WIN folder. Next click and drag file “mpe-auto.sim” over “HP3000”. Finally when the emulator shows the promt type “hello mgr.games”. Then you can select the game to play.
I know a very very very long not-for-young-people game using sugarcube format. Last time I checked it still was in development though, then I’m not sure it would count here.
According to howlongtobeat, a “speedrun” of Zork Zero takes one hour, 12 minutes, and 56 seconds
Deadline, on the other hand, took me two years to complete
If I recall correctly, the Monty Python and the Quest for the Holy Grail computer game has a button in the main menu labelled ‘Find the Holy Grail’, and if you click it, it says: “Congratulations, you have found the holy grail!” and the thing quits.