Kinda like what Midnightbyte said... minecraft-ish, but with a viking flavor. It has skills and equipment/food upgrades which sorta feels like skyrim-ish... without the endless questlog.. It's definitely more challenging than that game. It can seem a little grindy in spots, but I've had so much fun just building and exploring that the grind doesn't bug me. Every game like these has some bottlenecks in them... just have to choose what kind of grind you find acceptable. If you are focused on min/max instead of just what you want to get done then it will seem tedious.