TL;DR:
Love the game, but a few seemingly minor things absolutely need to be fixed (and they might not be what you think).
So in more detail, here are my first impressions. I'm not going to talk about all the issues, bugs, performance and crash problems as there are tons of threads on that.
For context, I'm playing SP-only so far, no mods, and ~140 hours in game, started on 1.5.0, then moved to e1.5.1 and to e1.5.2.
Key things I'm looking for in this game:
1. Fun melee combat. The game is ALL about the combat for me.
2. Siege immersion. I want to feel like I'm actually sieging a castle. I've never seen an FPS-style / action game do well in this area before.
3. Things that facilitate fun melee combat. This would include interesting combat and tactics AI, and interesting environments that allow me to fight in different places and different circumstances. I want to fight in the town, in the keeps, in the taverns, dungeons, in the villages - everywhere. Anywhere I can walk as a player, I want to fight.
4. Unique castle models for every single castle. I absolutely loved this in WB and WFAS. It's the reason I conquered those maps and played the games to the end. I just wanted to do a siege on every single castle to see what it was like. Many are based on real castles! Awesome! I can say I sieged a castle that exists in real life! Can't wait for this to be done in Bannerlord.
5. The ability to become a badass. I want to be able to level my guy up so high that I can take armies by myself.
Things I love so far:
1. Combat is great. Horseback with menavlion (high thrust) and shield is super fun, melee with 2h is super fun (love that you can take out multiple opponents at once with a giant 2h axe), melee with 1h / shield is super fun. Archery isn't really fun compared to WB but that's OK to me; it was too powerful in SP WB anyway. It's good enough in Bannerlord.
2. Sieges are extremely fun. Yeah I know everyone is going to freak out that I say this - because siege performance is totally broken. But they're still super fun! I love the way we're all climbing up siege ladders with shields up while rocks bombard the walls and the battering ram pounds at the gate, then I'm over the wall and weaving in and out of towers and battlements fighting little groups of enemies. It's awesome! Sure the AI isn't perfect. But it's actually pretty good, especially as compared to WB and WFAS (which basically just charged and ganked). Some silly things happen and I'm sure TW is going to improve the AI. But in general, I like it.
3. Many field battles are fun. I've been in some really interesting ones as a vassal where my commander formed shieldwalls that I ended up retreating inside while fending off greater foes, etc. My first impression of this was very cool. Of course it gets a little tedious later game but it's still good! I like it and I think the AI is cool even though I keep reading that everyone else thinks the AI needs major overhaul. It could use some work but it's not bad and facilitates fun fights as-is.
4. The leveling system is fun. Except of course half the perks aren't implemented! And the experience curve is horrendous when you get to higher levels. Blah blah, etc., yes, it's not done and needs work. But in general, it's a fun system and is going to be great when they're done. They're not going to release a game without perk implementations. So this will be fixed.
Things that absolutely have to be fixed and currently ruin the game (e1.5.2):
These things make the game essentially unplayable / not fun after a certain point for me. Even despite all the problems with the game - lack of perks, performance issues, frequent crashes, screwed up armor values, etc., I could still give the game a "Thumbs Up" on Steam even in EA, if my 3 things below were fixed. As it is, with those issues I would have to give it a "Thumbs Down" currently, if I had to rate it. Which sucks because I love the game. So here they are:
1. War declarations on my kingdom need to stop. Once I started my own kingdom, every other kingdom constantly declared war on me. It just wouldn't stop. I now own half the map and it still won't stop. I was having to save-scum for a while, but then I missed one declaration and didn't see it, then another, then another... finally the whole world was at war with me. It sucks and isn't fun, and isn't really possible to mitigate in any way that I could find. I thought there was a diplomacy update to this, but it doesn't seem to have affected my game.
2. Lord relations need to be able to increased in a major way without too much trouble. They just seem to decrease constantly for no reason to the point where I end up with -100 with almost everyone. Huh? It sucks and means I have to pay millions of gold to recruit lords. The inability to recruit lords effectively means I just have to execute all the higher level lords of enemy factions to be able to hold any territory, which sucks and makes things even worse. Relations can decrease but also should increase proportionally, or there should be ways to bribe lords to improve their relations. There just needs to be some way to positively affect relations in a MAJOR way without having to grind crappy quests (which you can't even do once you get too low). Rescuing someone, for example, should add a ton of relation. Sparing a life should also add a ton - you could have killed the person, but you let them go! Should be at least half of what you lose for executing people. Giving people a fief - should add a huge amount, and to all their relatives too. etc, etc. Just need some way to improve relationships with lords even if it's a hot-fix that lets me bribe them with 100k for 100 relation.
3. I need to be able to go faster than other lords on the overland map. It seems like such a small thing. But, the way it is now, just sucks. For example, with 1000s of speed-plus horses in my inventory, only my own party, and a Scout assigned with 220 Scouting and all the movement perks (which I guess aren't implemented?) AND the 10% extra movement from "very easy" in the Campaign Settings, I can literally corner a Khuzait ARMY (not even just a random lord) next to a concave shape in a mountain, and STILL can't catch them. They just wiggle out and slip away every single time. This totally sucks. I've literally had a time where I had to reload more than 50 times to catch one in this situation by just doing tiny little minor movement adjustments. And it was in the FOREST. Why are they fast in the woods? They should be slower in the woods, faster in the plains. This could be fixed so easily - in the campaign settings, just let me pump up the 10% speed boost to like 20-30%. Meanwhile, designers and devs can work on the perks and balancing such that the speed boost isn't necessarily when the game is actually released.
There are lots of other things wrong with the game, and things that need major improvement, but I honestly think just those 3 things (maybe I'm forgetting something) could be fixed, even bandaid-ed, and the game would be totally playable. I know everyone will freak out that I'm not demanding that the siege ladders get fixed, or that all the perks get implemented (although that might fix some of my issues), or the siege crashes or the AI or anything. Those things are kind of annoying but honestly not game-breaking for me. Yeah it crashes during sieges sometimes - so I just reload. Or, I know it crashes when I go up the siege ladder and leave the ram crew alone so I always go with the crew. There are ways around it. I could still play with the crashes and performance issues. But the 3 above things are absolutely beyond frustrating, not the least of which because there just isn't anything I can actually DO about them as a player. Even if I had a console that I could enable and then use a command to force a faction to declare peace with me - I'd be fine with that. I just need SOME way to handle it. For the beta, perhaps give players access to the console without a mod? Then we could just fix all the BS ourselves and get on with the game.