Unlimited time.
In Scriptwelder's interactive artsy puzzler 400 Years time is both on your side and working against you. You play a sentient stone idol who senses a great calamity approaching the world and sets out to stop it using the [arrow] or [WASD] keys to move. When you come up against an obstacle you can't get past, all you can really do is wait, and holding down the [spacebar] advances time through the seasons and years, allowing you to see the world (and the landscape) change around you until eventually the passage of time presents a solution. Though initially that solution is just "wait until you can go, but don't wait too long", the farther you go, the more you have to take a more active role in shaping the world around you, forcing you to think, explore, and act. The sedate gameplay (and slow shamble of the protagonist) won't appeal to everyone, especially since some of the places you're required to wait force you to do so for a long time. If you can both handle and appreciate that slow pace, however, you'll enjoy 400 Years for its lovely presentation and unique approach to puzzling solving. Though hopefully if we ever get a sequel of some sort, we'll get a more satisfying ending too.