Just completed A13 (Cassandra classic, temperate forest, mountains). Took me about 5 game years, ~4 days of game time (as per statistics). Launched all (remaining) colonists to space. Never played the game before (but watched on Twitch a bit). Now I want to share some thoughts.
First of all: well done devs! The game seems to have a lot of depth and replayablity. It's like a rollercoaster ride, just when you think you're done with the game, ready for everything that can possibly happen, things go horribly wrong. Somehow (at least in my limited experience) the game manages to avoid death spirals, yet doesn't become too easy towards the end.
It's not all good though, there are quite a bit of UI annoyances, excessive micromanagement, bad pawn behavior and badly balanced stuff. I'll try to list the big ones here:
* Friendly fire. Unlike other people here on the forums, I didn't have big problems with infestations. The biggest single incident was a grenadier throwing a grenade into a middle of my colonists meleeing a a bug (1 dead, 2 permanently injured). Friendlies event where someone brings grenades, the friendlies seem to be their own worst threat. And the sappers look pretty silly by grenading a wall while standing right next to it, ending up killing themselves and their teammates. Something needs to be done.
* General tendency of worker pawns to run into danger zones. Basically every time there's an infestation or a mechanoid ship, worker pawns just need to run into the room to clean up slime, or butcher dead insects, or repair turrets that are under fire by a mechanoid horde, and get themselves shot/cut to pieces without micromanagement intervention. The game does offer a solution of defining zones, but the dynamic nature of threats makes managing the zones a usability pain.
* Prioritizing building a blueprint. It's super annoying that the pawn hauls one stack of things, then forgets the priority. If I say it needs to be done right now, why do I need to say it like 5 times?
* While we're at it, why is there no area prioritize command? Get all these turrets built, right now, without me finding pawns and clicking prioritize a gazillion times.
* The enemies are very harsh. Yet they're not harsh enough. I had almost continuos ~15 day war against the machines (first a psychic ship in my front yard, then two consecutive raids). The ship event went horribly wrong, I admit I made serious mistakes there, and lost all my fighters (half of my population in total, burned in inferno flames along with their gear), making the two following raids really an uphill battle. And here's the thing: it was a battle I shouldn't have survivied. The centipedes took control of my outside yard. I was expecting them to breach my base and systematically hunt everyone down (not that there would have been much hunting to do, as all my remaining colonists were in the sick bay, either full of holes or trying to patch the said holes) and lit every square of my base on fire. Instead, they roamed the yard, randomly headbutting structures. I find it hard to believe they survived over 2k years without being a little more goal-oriented. When they finally, by accident I guess, breached my base wall, their disorganization allowed me to take them down by a blind man (lost both eyes, sight == none) with grenades.
* Another example of not harsh enough: manhunting packs (wargs in this case) don't finish off and eat their downs. I would fully expect someone getting downed by manhunting wargs to be ripped to shreds. I'd accept the behavior from non-carnivores, but a meat-eater skipping a meal? No chance.
* It seems that raids in general are not much more than a bunch of crazy people wanting to get shot by turrets. Sappers and sieges make much more sense, but even they don't seem to have any other goals than random death and destruction. Maybe add some goals for them (e.g. steal a bunch of stuff)? Even their in-game description says their equipment level depends on who they raided last, yet they don't ever seem to try and steal anything.
* And, talking about someone with no eyes. They seem to be very productive for being completely blind. Cooking, constructing, mining, smelting metal slags, walking full speed, seeing the ugliness of the world, suffering the dark. Breaking the immersion a bit.
* Still about eyes. Given the rate they're a-popping, any trader worth their silver would see the business opportunity and stock plenty of bionic eyes when travelling to a rimworld. The said colonist lived blind for about two years, I didn't see any eyes to buy. I hope they end up landing somewhere with plenty of spare eyes.
* And last, but not the least, the shooting accuracy calculation. It seems sight and manipulation are the king, and skill is nearly irrelevant. Evidenced by a skill 0 shooter (!) with sensory mechanites being a better shot than a healthy skill 12 shooter. Also, why does shooting a sniper rifle need two good eyes, it has a scope for one eye only!
And a collection of random suggestions and minor nitpicks:
* Mushrooms don't use photosynthesis (google it), why doesn't devilstrand grow in dark?
* Inferno cannon centipedes seem OP most of the time, but especially in the early game. They're like the storyteller's way of saying, F U, I will watch everything burn. And that is what will happen.
* Why doesn't solar flare affect mechs?
* Why can't EMP-stunned mech be subject to the shutdown operation? It would be thrilling, since you don't know exactly when it's going to wake up, two-headbutt the brave shutdown-attempting colonist to death
* Why can't we harvest bionic parts from the dead?
* More ways to interact with visitors please: offer them food and drinks and beds, and maybe they like you more when they leave (or maybe they like you less if you don't offer the basic courtesies). Maybe if the visitor-accesible parts are impressive enough, some of the visitors will join your colony? Maybe just try to recruit them without capturing?
* It would be epic if mechanite diseases would have a chance of leaving permanent improvements, e.g. turning basic prosthetics into bionic ones. This would go well with a strange and overwhelming urge to ingest some plasteel and components for materials.
* Pawns seem to be very cool with losing limbs or eyes. I know I would be quite upset if I lost an eye or a leg (esp. if the replacement is a piece of wood).
* General purpose shelves! There's already a gear locker, but it only accepts weapons and apparel. I hate storing my food on the floor where alpacas walk all over it and leave their alpaca-filth on it.
* A way to choose source material stockpile for a recipe (instead of radius)
* A way to ask a colonist to leave the colony, without arrest-release. Take what you're wearing and go. Of course, they're very unlikely to comply if you just told them to drop all their clothes and gear.
* A way to temporary detain a misbehaving colonist, without having to re-recruit afterwards. They may fight back if they disagree.
* A way to capture without incapacitating. People with survival instinct are likely to surrender when they're outnumbered and outgunned. Show them a couple of impressive miniguns (useless in a real firefight but they don't need to know that) and a friendly suggestion to come with us: an offer you can't refuse.
* The smallest possible ship has off-center thrust (because the reactor has odd, and the engine unit even width). As a KSP fan, this annoys me to no end.
There, I think I got most of it out. Now if you'll excuse me, I have a new colony to manage (Cassandra challenge, boreal forest, flat).