You know that meme?
"You have 800 hours in this game?"
"Yes"
"So you must be good at it!"
*Cries*
Yeah, that's me. But I keep trying nonetheless, as this game is just fun to figure out the problems to. Even though I have never launched a rocket. Or built a volcano tamer. Or really any functional midgame build beyond a water purifying system for the bathrooms.... hmm. I AM the meme, huh? xD

Brain too small but I like game <3

If you're reading negative reviews, you probably want to know about any dealbreakers that might make this game not fun for you. After 600+ hours of loving this game, I'm uninstalling; here's why. Hope this helps.

ONI has a dozen intersecting systems including air, light, heat, plumbing, food, power, critters, germs, automation, and decor. Overlays help you view each core system, but even so, a lot of things aren't intuitive. And once you get a handle your colony's needs, this largely becomes a heat management game with a side of space exploration. Heat becomes the main boss from the mid-game on, as most of your systems generate it, the insulating earth contains it, and it's tricky to counter it.

Other issues include a priority system for your duplicant colonists that dupes often ignore, wonky water physics, and odd quirks, like the fact that once something's built you can't move it: you have to destroy and build elsewhere, even just one square to the left. Also, mod support used to be great and the game was vastly enhanced by the modding community, but increasingly, mods make the game crash, at least for me.

Klei's flagship Don't Starve is a survival game that throws you into the deep end without explaining much. ONI mostly does the same, which doesn't really feel right for a colony builder. Both games really count on the community to fill in the blanks with wikis, tutorials and tips. Do you like to tab out of a game to go research why your plumbing backed up? You're in luck. If you love to consult wikis and ponder thermodynamics and enjoy setting up if/then programming systems, ONI is probably for you.

The first ten hours of a colony in ONI are mostly fun. I absolutely love the visual style. I enjoy watching the duplicants tootle around the map and munch on their meals and react to stress and happiness. I love the point-of-interest finds when you discover traces of previous colonies; I wish there were more POI puzzles and exploration. But that side of the game is incidental. Your ultimate goal is space exploration. Personally I find building rockets tedious and unrewarding in ONI. YMMV, but I do recommend looking up videos of players launching rockets to see if you'll be happy puzzling through ONI's many complications to get to that endgame.