This is a rare 10/10 game. Perfect in almost all aspects. Here are some key features of Elden Ring to consider:

Difficult Yet Rewarding
It's not an easy game, like any other Souls game.
It makes you learn enemy patterns, boss mechanics and most importantly what your character is capable of. Each boss is designed to punish certain player behaviors (one boss will punish for playing melee only, another boss will punish for constant movement, and so on). Some of the mobs are tougher than bosses. Environment will often be dangerous too.
Yet it will greatly reward you for overcoming those challenges and reaching a certain goal.

Open-World Reinvented
Are you tired of other open-world games published recently, such as latest Assassin's Creed or Horizon or Far Cry? Where it feels like enemy camps were just copy-pasted all over the world just to artificially prolong the playtime?
Well this game is different. Each area is unique, mobs are different, not just visually but also have different mechanics. The exploration is real in Elden Ring, you might revisit a low level area later in the game and find something new, something useful.
This is probably the biggest achievement of Elden Ring and I hope other game studios will take a note here, because this is the future of open-world games.

Art
While graphics are not the best (UE5 is better), this is one of the most beautiful games i've ever played.
The art team has made an incredible job. All these epic models, various biomes, beautiful sky, ambient music, and so on and so forth. You can tell that this game was created by people who actually care for the game. Every small detail was considered.
It's hard to pass the feeling when you go underground and find a peaceful river with artificial stars on top of it, or when you descent to burning lava cave or reaching the top of snowy mountains with giants.

Lore
GRRM did a great job here. It's not that Dark Souls series had bad stories. But Elden Ring is on a completely different level. I wish he puts the same amount of effort in finishing Winds of Winter.
And it's not just lore, but also the way the story is being told, it doesn't just push cinematics or walls of text over your face. But rather each NPC gives out portions of the story over time. Sometimes you won't even pay attention to what this NPC said but later will figure out how important that small piece of information was.

UI
This is another aspect I have to mention. Most of the time there's little to no interface on your screen. You're actually playing a 3D game without tons of 2D elements/text on your screen. In combat it'll show minimum amount of information necessary for the fight. You don't have a special journal with arrows and map markers for your quests, but rather have to rely on your memory and decide on your own where to head next.
It really helps with the immersion, i think FromSoftware has proven that this approach of minimalistic UI is more than functional in an open-world game.

Cons
- Some minor things like the confirmation popup to summon dead horse while fighting a deadly dragon... this popup needs to be removed.
- Controls are not easy to learn for newcomers.

Overall, it's a masterpiece. Don't think about it, just try it, you won't regret!