Drakensang is rare epic RPG and is IMO a musthave/mustplay. Even people who're not into RPGs should try it.
It's not cheesyeasy like plenty of RPGs, on the other hand it's not unforgivable like another TDE based game Blackguards. But most important, it's not a grinder where you need to collect some souls or something to win boss fights.
Don't ask me for an explanation of no international success - if it wasn't for a few obscure sites back then, I'd never even hear about it.
There is something else special with Drakensang.
It's UI is so PC centered, you will never see that game, or something with similar mechanics, on consoles nor on phones/tablets.
The day I see Drakensang on phones will be the day I'll accept phones are spectacular as Apple wants people to believe. Never, right? Who knows. But till then, I'll think of phones as phones and virtual beggar slot machines.
NWN you say? Baaaaaaaaaaaaaaaaaaaaaaaaaaaaaah.
If someone never bought that one, do me a favor, skip it. Your time is too precious to waste on such stuff.