In Risk of Rain, time = difficulty. The longer you play the harder it gets, do you tear through the levels as fast as you can or do you spend time collecting some of the many ability granting artifacts? With randomly generated levels, giant bosses and just one life. How far will you go?
Chalenging in every playthrough, however when you repeat several worlds it might start lagging or crash. Also the Online Co-op crashs sometimes, with no possiblity to reconect. Except those problems, a great game I enjoyed greatly