The people who made Mysterium want you to play it wrong. That's not a problem with the original board game, as long as you don't play with people who insist on adhering to the designer's vision (hot tip: just don't tell people about the extra faff and keep the timer tucked away in the box). PC players can't be so picky.
Mysterium is a cooperative game where one person is a ghost attempting to tell the other players how they were murdered. Just like real ghosts, they can only communicate through dreams - here those take the form of surreal images handed to each player every round. They're trying to nudge the living players towards one of several possibilities from that Cluedo trinity: the who, the where and the weapon.
The allure lies in trying to fathom what earthly reason the ghost had to pass you a picture of say, a chimney sweeper on a flying penny farthing. Doing that in just your own head is fun, but not nearly as much as talking it over with a group who are all equally baffled about what's going on in their friend's mind. That's where the rules get it wrong, curtailing that chat with a two minute timer rather than letting it go on for as long as everyone wants.
When I play the board game, I pinch a trick from Codenames and give people a one minute timer they can flip when they get bored. I'm glad a PC version of Mysterium exists, but as a testament to the power of home-brewed tweaks rather than as something I'd necessarily recommend.