Just finished the SP and it was really nice, classic gameplay enhanced by some stuff like runes and different weapon upgrades. Really like it, although it could have been a tad bit longer, tried Hardcore Nightmare but died when i fired a grenade into an Imp close range full hp. They need to remove all the cutscenes and stuff from that difficulty to make it faster.
Also nice that the endboss can survive more then 10s this time around

, nothing like Doom 1 where you just spray him with two BFG hits.