BD is still available online (eBay, etc).
Was it poorly received? The Wikipedia reference says 'mixed or average reviews', but from skimming over some of the lower scored review summaries, at least some of the complaints don't seem very valid. Several complain about the battlefields, a completely optional area they could have easily skipped, while others apparently didn't read much and missed the plot. One thought having two characters made the game overly complex (most of the time you can direct them to move or attack together, and even when you need to control them separately it is just not that hard).
I think most people who liked DD and gave the changes in BD a chance liked that game as well, mostly to about equal or lesser extent. People who just wanted more of DD complained about being disappointed.
Probably the most significant change is the game world. DD was very open, and from the start you could head to almost anywhere (though you wouldn't necessarily last very long in a fight). BD is divided into 4 acts, the first of which is fairly linear until you reach a certain point, and once you enter the next act you can not return. While this makes the game less open it does make sense with the story (once you escape a prison, for example, you are not going to want to visit again), and from a design standpoint makes quest design, testing, balancing, etc easier.
DD starts off in a village with plants and trees and stuff around, and you can interact with some NPCs and do some non-combat related quests. The first act of BD in underground, where you only briefly see any greenery. There are a couple quests near the start, and limited NPC interactions, but the prison setting doesn't lend itself to well to non-combat quests. Once you get to the second act the world becomes more open, with different environments and scenery.
The start of BD could have used something like DD's existential skeletons...
The stat system was updated in BD, with 6 primary stats, rather than 4 as in DD. Some people thought this made things too complicated, but I liked it, and it allowed much greater flexibility in character development. For example, in DD pretty much every warrior ever created ended up neglecting intelligence and distributing stat points as 2 parts strength, 2 parts agility and 1 part constitution. In BD there are many more ways to create a viable warrior.
The skill/spell system was replaced. Rather than skills simply being level based, you need to learn a skill from a book or teacher in order to be able to invest skill points into it and use. Most skills are available from different teachers, in case you miss talking to one, and depending on which skill classes you choose starting the game, you begin with certain skills available.
The skills themselves are more flexible and customizable than in DD, and you can unlearn skills (for a price) to reinvest elsewhere if you wish. In a couple cases the skill system is more complex than it needs to be (ie separate weapon expertise skills for regular swords and shadow swords, etc), but overall is much more flexible and customizable than in DD.
A few people complained that BD had more skills (with more levels) but you end up with fewer skill points to use. However, you do not need to max skills for them to be effective (for my archer, I maxed Reload Time in the bow/crossbow expertise skill, but only put a couple points into the damage and accuracy bonuses). I kept a fair number of skill points in reserve (in part because I was thinking of adding different weapon expertise and maybe playing with traps or other spells eventually, and in part because of people complaining there were not enough skill points), and had no problems with my warrior / archer combination. Even with a mage, though, more powerful and mana efficient spells (particularly shaman magic) start to become available in act 2, so earlier spells can be unlearned and replaced with a few of the more effective spells.
There is a
demo (168MB) available you can try, which includes the first level of the first act in the game. As with DD, the beginning was designed to be relatively linear. After the demo was released there were a few additions made, like party selection and screen re-centring hotkeys, and the voices were re-recorded (opinions differed on which were 'better').
I've not been able to locate BD for quite some time now, but I'll keep searching! 
As for me and 
, I'M STILL 
first to be able to play BD, but it was nice sometimes, because of the reference to previous jokes and characters. 
![[Linked Image from squirrel.ovh]](https://squirrel.ovh/smilies/bartanewban-sm.jpg)