Older games often offer more challenges and are often unforgiving to non-optimal playing.

examples:
Bards Tale 2 (1986)
Wizardry 4 (1986)
Dungeon Master (1987)
Might & Magic 2 (1988)
Champions of Krynn (1990)

They are often harder to play than modern games, because they have to be mapped by pen and paper, saving is often only possible at certain locations (adventurers guild …). Turn based demanding fighting is often the essential element of the game.