Finished it, twice. Loved it, albeit with caveats.
Pros
+ Drop dead beautiful game. One of the best-looking games ever imo. Superb visual design and lighting. Top notch actor modelling and motion capture.
+ I really liked the combat. There's room for improvement, but the dodge mechanic is surprisingly tense and fun once you master it. There's nothing else which feels quite like it. I went from bumbling around like an idiot on my first normal playthrough to coming through battles without a scratch on hard mode. I like how gun use is divided between ranged combat and combo finishers. Earning your chance to do big damage and take out tentacle guys quickly feels great. The GRP system is immensely satisfying but it can certainly trivialise certain encounters. But honestly, that's kind of awesome, and it feels like resource distribution is balanced around it, especially on hard.
+ It's surprisingly unique. For all its blatant theft of Dead Space, it comes across as more of a hybrid of Dead Space, The Evil Within, and The Last of Us. A lesser clone would make me wish I was simply playing one of those games instead, but I feel like Callisto is doing enough of its own thing to stand out.
+ Incredible sound design. There's even some nice music in there which was a pleasant surprise.
+ It's paced fairly well despite the abundance of slowly crawling from one RAM heap to another. My second run had me tearing through the game and I think I actually enjoyed it more. There's enough variety in combat and exploration to keep things enjoyable during the game's fairly short run time.
+ I didn't want it to end, and I felt it ended too early. I see this as a positive rather than a negative, because what's here is a very good time imo, and 9-10 hours of entertainment is nothing to write off.
+ I liked the characters and thought the performances were great. Duhamel has broadened his range of expressions significantly since I rolled my eyes at him in Transformers. Witwer was particularly good.
+ I actually kind of like the fact that there's no map. It made taking steps into the unknown daunting, and while I can appreciate that wondering if you're going the right way is going to be frustrating for many, I personally admired the game for asking me to make potentially risky decisions and stick by them.
Cons
- I don't often play games for the story, but The Callisto Protocol's story is shamefully derivative of Dead Space. It's a beat-for-beat reshuffle of Visceral's original for a new generation. That said, I wanted to see how it turned out, and I'm looking forward to the DLC shedding new light on the game's world.
- Callisto would hugely benefit from more battle variety. This type of game thrives on the synergy which develops between enemies, weapons and environments of different types. With Callisto you essentially have four choices- defend, melee, shoot, or GRP. Most of the weapons have very similar properties, and GRP is usually an instant kill with the trade-off that you can lose that enemy's loot. It's one category where comparisons with Dead Space are unfavourable, because you were encouraged to deal with different enemies in uniquely optimal ways. In Callisto, with a few exceptions, every enemy is fair game for the same strategy. It's a fun strategy for sure, but I would like to have been pushed to try new things.
- I missed the puzzles and environmental challenges of Dead Space, of which there's very little in Callisto. Stuff like the asteroid blasting scene (fuck you I liked it), the radioactive balls, basketball, the shooting range etc were sorely missed. Callisto is a very geographically straightforward game in comparison, which may have been intentional to sell a more grounded setting, but other games in this genre like RE4 and The Evil Within show how it pays to throw weird and unexpected level design at the player.
- The game has its share of bugs and weird incidents. The save/checkpoint system is incredibly inconvenient and inelegant. The weapon select would often give me a weapon I didn't ask for. The lip sync is off in several scenes and looks weird as shit. Overall it's a very polished game, but more could be done.
- The amount of crawling through spaces and ducts is kind of ridiculous. I get that visuals of this caliber on last gen consoles comes with a price, but I'm fairly sure the PS5 I played this game on doesn't need to be held hostage by quite so many awkward instances of holding 'up' for half a minute.
It would be a crime if this game didn't get a sequel, because there's so much good work done here, with so much potential. Callisto 2 with more enemies, more weapons, more environmental variety, less blatant loading gates and a longer length would be incredible, and a contender to stand alongside the greats in the horror TPS genre.