Doom was a bit samey but I feel like it didn't overstay its welcome too much. It's always introducing new stuff like weapons, upgrades, enemies and ramping up the challenge while you're at it. It's fast paced and challenging while being rewardingYeah you described the first game there and I agree its a very good game. It starts to go stale in the second half because it stops introducing new weapons and enemies but it doesn't outstay its welcome, like you said, so it finished before I could actually get bored. I just felt let down by the second half of the game getting so repetitive.
The problem with Doom Eternal is that its all the same, the weapons are the same ones you had in the last game, a lot of the enemies are the same, the core systems are the same. So what made Doom interesting, there constantly being something new, is just not present here at all. It just feels like the second half of Doom stretched out over an even longer game, which is why I'm so bored of it.
The challenge doesn't even ramp up in Doom Eternal either, its actually getting easier. The few changes they've made to the game are actually for the worse, which doesn't help, but it made the start of the game where you only have a couple of guns and not all the unlocks like the flame belch just stupidly hard, now the game just gets easier and easier as you unlock more stuff, adding another reason for the disinterest I have.
I'm not sure if I'm even gonna carry on with it, this is another case where I'm baffled by the review score, I don't know what people see in this game. Yes its obviously very competently made overall and is fun if you just really enjoy the Doom core gameplay loop but it doesn't offer anything more.