[coroxout]

I think the site author comes from an interactive fiction background, so I suppose there were text adventures that did switchable playable characters and time travel before DotT [1], but I don't know of a graphic adventure that beat DotT to it. I found the interaction between the 3 timezones pretty innovative as a kid too and think he does the game a disservice here.

It also opens the game up in terms of how many puzzles you can be thinking about at once; if you're stuck in a traditional 1-protagonist game you might only have one or two things you think you need to do next, at least in a pretty linear game, but now you always have at least 3 things to work out at once...

[1] I'm not a big IF buff, but I guess Infocom's "Suspended" (1983) is a classic game where you can control different "characters" at once, and I really loved "T-Zero" (1991), where you also open up 3 different timezones you can travel between at will, and changes in the past affect the present/future in a slightly DOTT-esque manner - although it's a very different game.

Suspended: https://en.wikipedia.org/wiki/Suspended_(video_game)

T-Zero: https://ifdb.tads.org/viewgame?id=u8qqrwutdugkexpr or reviewed on filfre.net here: https://www.filfre.net/2017/12/the-text-adventures-of-1991/

[ilikehurdles]

Chrono Trigger was a really good old SNES RPG that had gameplay centered around time travel, where actions in one timeline affected outcomes in another. Not an adventure game, but it's something that your comment reminded me of.

[needle0]

Much less known than Chrono Trigger, but the Game Boy RPG SaGa 3 (known in the west as Final Fantasy Legend III) was a case of Square's attempt at time travel in RPGs that came before CT. It had a lot of thematic elements in common, eg. actions in the past affecting the future, objects that appear in all time eras, separate dimensions that exist outside of the regular time continuum, etc. Unlike CT or DoTT, the eras were only decades apart, so you could also run into the same person as a kid and an adult. The same team at Square did not work on it, but it should have at least had some influence on CT.

[logfromblammo]

Zork III (1982), Sorcerer (1984), Spellbreaker (1985) and Trinity (1986) all did time travel, and Suspended (1983) did multiple characters.

Zork Grand Inquisitor (1997) definitely did time travel as different playable characters in a graphical adventure, but that was four years after Day of the Tentacle (1993).