A couple of roguelikes work this way. ADOM, in particular, gives you a very fixed period of time to save the world from an incursion of Chaos before said incursion and its radiation-like effects start making it very much harder.
A couple of roguelikes work this way. ADOM, in particular, gives you a very fixed period of time to save the world from an incursion of Chaos before said incursion and its radiation-like effects start making it very much harder.