One of those things where sections of the floor fall away and the rest moves together and apart in different patterns? It happens all the time in video games, I know that. (This is the worst description of anything ever. Sorry...)

Also, one of those balance-y things like they had in whichever National Treasure movie it was: basically, it's a plank of wood balanced on a log that tilts super-extremely from side to side. Basically, you can only get off if people stand in the corners with a relatively even distribution of weight and then use momentum to propel one side safely up to the ladder-type exit.