Having run many a D&D game, I can tell you that players generally don't like a hard clock. It can be nice to have a stick to drive people forward a bit but overall the trope of a McGuffin is typically more enjoyable.
That might be true in scenarios without time travel but video games are all about a flowchart of events and how you can order and effect them.
Its more that if you have 50 days until your head explodes, and every fight you do makes you rest, youll eventually stop exploring because it means fighting > resting > exploding. People will typically try to clear the clock ASAP and then go back (in a game). In D&D they just ignore stuff because you can only have 1 priority at a time and if one has a stop dead date, you do that. Instead of "Lets go have an adventure and see what is out there in this crazy world" it becomes "HURRYHURRYHURRYHURRYHURRYHURRY". Technically, you can probably get away with it, but if I thought I was going to explode, Id not have done 80% of what I did. Id go to BG / moonrise ASAP and then just assume I can grind out XP later if I am underleveled. Your reputation gets damaged in this with illithid stuff and its just generally a negative weight. Even the "cool" powers are at a price. Having never used the in one playthrough, yeah it can be less stressful, but as soon as you do the clock starts ticking louder.
Rushing is usually not fun, and I am having a hard time thinking of my favorite "ticking clock" games. Youd think Diablo would have had one as hes entering the world through a ritual, but im pretty sure id have enjoyed it less if I had a deadline to get to him.
