It's a load of fun, and I am thoroughly enjoying myself, though I would say it's a little lacking in content, at least in that there are limited things to do.
1.) You can craft new equipment and items (food, potions), as long as they're of your level and of your class. You do this mostly by gathering materials from the world and buying/receiving formulas.
2.) You can explore by traveling, hang-gliding, riding, climbing, swimming, and sailing.
3.) You can level up endlessly.
4.) You can go on "missions", which are markers on the world map for dungeons and or bosses that refresh every in-game day, granting you extra XP for emerging victorious against those bosses.
5.) You can use Pet Food to collect pets ranging from animals to monsters. This feels a bit like Pokemon, and at the moment it's not necessarily known which food will attract which pets.
6.) You can use port forwarding on your routes to join a multiplayer server. Up to 4 players together.
Certainly enough to keep you occupied alone, and even more so with friends, but I feel it could use more to do in the long run. But of course it's an open alpha, still in development and all that.
Have a screenshot: