[chii]

The time limit was a bit too arbitaray. I think instead of failure, a time limit on extra rewards is more favourable. The Xcom enemy within expansion did it right by making a time limit hidden (with sound clues) for the extra "meld" reward. You could split your team and hunt for the reward, but risk trigger multiple enemies, or forfeit the reward for safe play. The player is in the control seat, not the game.