Depths of Peril is a single player action RPG with strong strategy elements.  You play as a faction leader protecting the barbarian city, Jorvik, by destroying threatening monsters and completing quests. At the same time, you compete with rival factions to see who will rule the city. Barbarians choose their leaders by fighting to the death! 

In the Depths of Peril demo, you can play all 4 characters, explore the first part of the world, play through part of the storyline, experience a lot of the dynamic world with consequences, and get a taste for the covenant gameplay and it's only around 70MB.  You can see the minimum and recommended System Specs here.