Bought the deluxe edition and have two days off work to play, so am getting really into it. Just a few points from someone who absolutely loved Returnal:
Initially the controls felt a little off, I think this was mostly the remapping and having to consider the shield (which felt delayed at first, but I'm starting to feel like the animation just makes it 'look' delayed). I personally remapped most of the controls to resemble Returnal (dash on circle, scan on R3). However, I've put the shield back on L1 (might have been R1 default, can't remember) because even though melee on square felt 'right', I was finding that it was limiting my ability to keep moving whilst using the shield. The only issue I have at this point is that there's no sprint option: I'm aware that holding dash will eventually 'sprint' but this only works out of combat. It seems like Arjun is constantly sprinting, which I reckon most players will be fine with (as have seen a lot of people put auto-sprint on for Returnal), but I quite enjoyed being able to switch between the slower/faster movement in Returnal. Otherwise, controls feel great, responsive, and as second-nature as Returnal does after 5 hours.
General gameplay is super satisfying, although took about an hour to build into. Think I was getting used to the way the shield comes into play and how the alt-fire mechanics work, but I'm used to it by this point. I'm a huge fan of both the shield mechanic and the 'rocket-launcher-like' power weapon - it adds a whole new dynamic to the bullet-hell dance and is resulting in a completely different approach to gameplay.
Difficulty wise, as someone who can reliably play through Returnal, it actually started off fairly tough. Not too tough, but tough enough. I was able to kill the first boss after 3 runs, but it was close and felt like a good enough challenge. I reckon most players, especially people new to this, would still struggle quite a lot with the first two biomes. The Eclipse mechanic is super cool and does add a decent amount of challenge.
I'm enjoying the armour upgrades and ease of jumping in and out of runs. The game still gives you the option to run through biomes, and it benefits you to do so as you retain all the progress from the previous. I actually haven't beaten the second boss yet (got to the second phase in my 3rd run) as I've been happy enough just playing through the first biome a couple of times to build up some Lucenite for upgrades.
Story wise, I'm happy enough with it so far. On one hand, it's refreshing to have a cast of characters and a fresh story. On the other hand, I feel like I ultimately might prefer the way Returnal told its story as there was something isolating and thought-provoking about being the only human in Returnal as opposed to having a more direct story provided to you but I've yet to make a final decision on that. Happy with it so far, and have been invested in the dialogue/lore/characters.
Graphics and audio are top-notch, which I expected from a follow-up to Returnal. Nothing more to say on that really, it's as perfect as Returnal was in that regard...
Seen a few bits about people not being sure about the guns, and I am a little disappointed not to have seen things like the Rotgland Lobber but as I'm not that far into the game yet I'm going to reserve judgement on it. I'm actually enjoying the guns at the moment, and the way the traits/modifiers come into play alongside the power weapon, but have found the shotgun to be quite underwhelming so far...
On the whole though, having a lot of fun and super excited to play more. Jumping back in to play through the first biome and hopefully defeat the second boss this time round.
Definitely worth a buy if you're on the fence!