We all like a good challenge, but that is where Eternal failed. Because a 'good challenge' is something just outside your comfort zone. Something that tests you, but is 'reasonably' easily achievable. Not something miles outside, requiring a herculean effort!
For most 'casual' gamers, Eternal was just too big a step in too short a time. For those casual gamers, not enough time is given, and precious little instruction, to learn, and develop their skills with these new things, before being dropped head-first into the thick of it.
Eternal gets 'more' fun if you take the time to learn the mechanics, which again, the casual gamer isn't going to take the time to do.
Most games from the first doom to doom2016 are basic 'run around, WASD, fire your weapion of choice'. The majority i would say are happy with that. They didn't want to join the GB acrobatic team, they didn't want to have to master the speed squirts, or juggle the different grenades (on the same button which to me makes it worse). And i bet they didn't want to have to farm armour and ammo with flame and chainsaw.
These things of course, like most things, you get used to...(especially if you use a script
) given time. But to throw em all in at the same time? Misjudged imo.
The 'hardcore' gamer will accept the challenge and adapt, and the 'casual' gamer will get bored and move on.
Totally understandable.
Btw, i'm too old to be hardcore, i was just bored