One Chance is a Flash game developed by Dean Moynihan and released on Newgrounds on December 2, 2010. It has been frequently cited in video games literature as an interesting and moving use of permadeath mechanic (permanent death).
In the game, the player controls a scientist who has created a cancer-attacking “cure”; when it is released in a gas form it begins to cause the extinction of all life by unexpectedly targeting all living cells, rather than just cancer cells. The player is given six days to create an antibiotic, after which point one of several endings may be achieved depending on the choices made. A web browser cookie prevents the game from being played more than once.
A small, simple game that makes you feel something.