That's why he only streamed 25 minutes at first. Supposedly that was how long it took for them to ban him from twitch.
To be fair to the game, I saw some comments from the guy on Reddit mentioning that he was having fun with the game, although it did have some flaws such as the way fighting was (combat alternated between being very easy and very very hard, but was always really simple) and generally unbalanced, which is why he was able to beat it in 30 hours, by farming an item which would lower the cost of goods on the market and using it to buy all the important shit he needed. Pretty much everyone hopes that item gets a nerf, but I'm not sure if it'll happen or not. He also mentioned that there were several game-breaking bugs he encountered, although he was naturally playing an un-updated copy and there's a 99% chance that they'll be fixed in the patch they've been working on once the game is released for real.
When he says "Finished" he means he got to the center of the universe-galaxy-thingie. Naturally there's still stuff you can do afterwards, although he was already super-powerful and rich due to the balancing issues I mentioned earlier.
Although I didn't actually watch the stream, overall I'm still looking forward to playing it, despite its flaws. I wasn't expecting it to be some super-perfect game.
Also, I think I saw a post on Reddit mentioning you can name rocks. That's fucking dope.
EDIT: I'm just now realizing that he might have meant planets when he said "rocks".