One Chance is an interactive narrative adventure game where you literally only get once chance to save the day, and seems to be developer AwkwardSilenceGames's attempt to live up to his name. You play a scientist who is part of a team who discovers a revolutionary cure for cancer, but the celebration is short lived when you realise the cure is actually a death sentence for the entire planet... a gas-based drug that rampages through all living things. You have six days before life as everyone knows it ends, and it's up to you to figure out how you want to spend them. Use the left and right [arrow] keys to move, and the [spacebar] to interact with people or objects. Be careful about the choices you make, since you can usually only choose to do one thing each day, such as work.
When the game says you have one chance, it means it. There is no replay button. If you fail, you fail for good. Once the game ends, you cannot play it again, unless you're particularly savvy and "cheat" by disallowing cookies to be stored on your computer, or clearing all your temporary internet files from your browser. To say this has caused a polarised reaction from its players is a mild understatement. The developer has said he wanted to explore the concept of permanency in games, and to get players to really think about their choices. Guilt and responsibility often go hand in hand, but it's entirely up to people as individuals how they react to their mistakes; whether they decide to do everything they can at the cost of themselves to try and make things right, or simply accept things as they are and shrug their shoulders.
It's an ambitious attempt at connecting with the player, but for some its attempt to try something new with its mechanics may wind up being a nail in the coffin. While it's acceptable that shirking work results in a lost day, why in the world does walking up onto the roof of the building to have a short conversation with your boss take an entire day? Five seconds of conversation should not count as wasted time when you can literally spin on your heel and be back down at the labs hard at work in just as long. For me personally, things like this acted as blocks that kept me from ever really connecting with the story emotionally. Which is kind of a shame, since the story here is intended to be some pretty grim, introspective stuff even though it's only told through short pieces of dialogue.
Structurally, One Chance will probably remind some gamers a lot of Every Day the Same Dream, which the developer admits was an inspiration (along with Babies Dream of Dead Worlds); the area design in almost identical in a lot of cases, although the stories are completely different. Seeing the way the world changes around you as the days roll by is a little alarming; some differences are subtle, such as the trees that slowly begin to wither, while others like the rioting protesters who begin to appear on your way to work are harder to ignore. There are multiple endings depending on your actions, but as we've discussed, you're probably only going to see one of them unless you take other measures (or play on another computer). I wouldn't call One Chance an "art game", but rather an experimental one. Whether you think that experiment was a success or simply a questionable design choice is entirely up to you.