Space Marine 2 is a great gateway to Warhammer 40,000. Enjoyable enough in itself, but also tied into the surrounding universe enough that someone new to the franchise might want to look up some lore. The campaign mode is set around Lieutenant Demetrian Titus fighting in the tiniest sliver of the overall galaxy-wide war, but it manages to feel important even to veterans of the 40K franchise. The writers managed to include Space Marine 1 and 2 to canon with a bit of clever storytelling (that's why Titus is a Lieutenant now, instead of Captain like he was in SM1), which allows it to be taken seriously by even the gatekeepiest of fanbases. Overall the campaign is enjoyable, and it feels like you're a superhuman in a massive suit of armor, taking on ravenous beasts and improbable odds.

Main replay value (at least for me) is the Operations mode. They are closely tied to the campaign, and remembering where you were in the campaign when Titus said this or that to the other squad links the operations to the specific events of the campaign. Grinding all the weapons to Relic tier is great, I enjoy when my pea shooter actually starts to do damage, as I unlock new weapon tiers and perks for the class. The enemies feel diverse enough, even though Tyranids and Chaos enemies both have small shooters and big melee fellas, as well as big shooters and small melee fellas. Bosses spawning in at random is a cool addition, it brings an added feeling of diverseness to a repeating set of missions. Also playing dress-up with your Marines is nice, there's a lot of customisation options with armor pieces and colours.

The PVP feels like such an afterthought. I played it just to get the 100% achievement, and frankly it was quite enough for me. The maps look and feel like they were made in Halo 3's forge mode, and the balance is way off (at least of late Oct 2024). I've seen people play the PVP mode exclusively and get good at it, and hats off to them for being able to grind a mode that feels shallow like a puddle to me.

Adding in Operation #7 is the beginning of the roadmap for SM2. OP7 brings in a new boss fight, conducted rather differently than the previous boss in OP2. The new operation is a fresh addition, even though the overall hue of the map reminds me of the yellow/brown filter era of late 2000's and early 2010's games. The new difficulty, Lethal, provides a new challenge in "tethering" the players together by having armor not regenerate outside of a certain radius of your teammates. Some people are mad about it, alongside the otherwise raised difficulty. I think it is reasonable as Lethal is supposed to be the ultimate challenge, and anything meaningful to progression is not locked behind it. Solo carrying Ruthless is not that hard, but it's near impossible on Lethal.

Overall, the game is great. It has a lot to do, even though it's not this "second life" tier of game, which we are now getting used to. Combat is satisfying and gory, it feels like the ultra-violent setting of 40K is supposed to feel. PVP is meh, but Operations carry this game, and if the devs stick to their roadmap, it's going to be a great ride for the next year or so.

Edit: The tether mechanic was quickly removed from Ruthless due to backlash from the community. I don't mind, it's w/e to me. I'll leave that part in just to remember that there was a mechanic like that, a long time ago.