A lot more linear, sillier, and at times clunkier, but still pretty similar.
the skill system sucks but stats are slightly more fine-tuned, though you end up abusing luck all the same. For example my main hero has over 100 luck right now and any 'semi tough' enemies I kill end up dropping incredible loot with something like 10+ bonuses, money's flowing like crazy too. I liked the old unique skill system that div1 had, BD kind of breaks it down to the point of "what kind of damage do you want to do?". Magic is damn near unusable considering its absolutely ridiculous mana costs. Many skills/abilities themselves are also useless past a single point. For instance in 2-handed weapon proficiency the first point you put in accuracy gives you +80%, damage gives you something like +8-12 damage where-as subsequent points give about a tenth of that, so you end up with a single point in quite a few skills. Good thing is you can 'delete' skills whenever for a gold-cost and just redistribute your skill points -- pretty useful when all of a sudden you desperately need lockpicking or alchemy or whatever.
You also can't put points into a skill until you learn it from books or NPCs, many such trainers will say teach you "level 8 1-handed weapon proficiency" which allows you to put 8 points in any 1-handed weapon proficiency which goes something like: 1 handed -> damage type -> accuracy, damage, crit, death blow, etc. So you relegate all bonuses to damage type given (there are elemental weapons a plenty).
Then there are some skills like 'sharpen' which add an incredible damage bonus with an added Agility requirement to the weapon -- you can easily triple the damage done with only a half-dozen points in this skill.
Roughly put, loot/equipment is pretty fluid in the game and you never really get a "favored" weapon, which is itself cool cuz you just end up using whatever you want -- or on the flip side -- you end up re-analyzing your equipment every 10 minutes when some new Great Shadow Axe of the Dire Hound is found, or whatever.
The battlefields are basically Diablo-spoofs, its item naming schematic is also equally absurd, but the main game itself is relatively entertaining. I would say that if you were okay with the Aleroth Catacombs in Div1 then you'll be fine with BD -- as it is pretty much that just expanded on. Really long dungeons that have traders/interactable NPCs in them with lots of silly humor. The first actual 'village' you come across is the imp village in chapter 2, chapter 1 takes place entirely in the citadel but it too has shops and people you can talk to and trade with.
The quests, when you finally come to them, are just as varied and multi-pathed as in Divinity 1 -- sneaking around, gathering evidence, using your brain before you proceed, all that good stuff.
It also has surprisingly more gore spread around as part of the scenery than Div1 did.
Voice acting is wayyyyyyyyy sillier.
