Confusing the players goals like that isn't a half bad design philosophy. designing a game around that concept wouldn't be half bad if you took some time to refine what its driving core is. A game loop boiling down to: Spawn in, avoid distractions, find your goal, achieve said goal. it could make for some good replayability if the goal is new each time. the only difficulty would be that your communication to the player would need to be rock solid.