The game is very similar to this except it's impossible to do it all in 90 seconds here.
Rules are simple: starting person makes a scenario and starts a sentence with a letter. The next person starts another sentence with the next letter, the person after that does the same and so on. When we eventually reach the starting letter, the person who hit that letter creates a new scenario, picks a new letter, and it starts over.
Example: (starting letter = B, scenario = the office building's on fire) Person 1: "Bring me this month's financial reports." Person 2: "Can't you see the building's on fire?" Person 3: "Does it matter?" Person 4: "Everyone else is evacuating."
Ok now it starts Scenario = You're on the Titanic when it crashes into the iceberg; Starting letter = J
Okay, wait! *A huge man with a white beard, a crown, a trident and a bunch of seaweed rises from the ocean* Hello Poseidon, can you please bring that whale over here? *Poseidon refuses and heads back underwater* That failed.
Quick! Come back here or I'll start calling you Neptune from now on! *A massive wave starts coming at our ship* I guess this is what happens if you anger the sea god.
Zip you stupid mouth aamer13! You are ruining the experience! *Loads harpoon and shoots the whale shark* Just to finish things off. Now drag it up the boat!