Originally posted by Lecherous Lychee:

You can play it solo and go at your own pace. Just make sure to watch your back when exploring, and eat the right combination of foods for stamina/health. Co-op just makes it easier, but could also be more of a pain if you play with the wrong people.

Even though the game has multiplayer, ultimately, there aren't enough controls/options that allow tweaking of multiplayer worlds. Also, there is the thing with security and 'cheating', as well as some players going far ahead of others, making the world more difficult for newer players.

says it all

yes you can play it solo (playing solo for 700 hours now) - but take your time
set your pace as you like

i must add:
some things may take some time to find out but dont be afraid to try