For contex, I have a platinum, played on give me gow twice, about 80 or so hours on total counting both runs.
The game does not have a lack of enemy variety problem, it has a lack of boss variety, it has a bazillion different normal enemy types tough: fast draugirs, heavy draugirs, long range draugirs and the flame sword draugirs are different enemies, and then you have hellwalkers, ogres, revenants (3 different types of them), travelers (3 different variations of them), wolvens, wolfs, those anoying lizard like creatures, night elves (3 different kinds of them), nightmares, those lanter bearing hellwalkers and theres probably more stuff Im forgetting. Theres also a couple of execution animations per enemy (yes the executioners cleave does count).
And the story of this game is the way it is on purpose, the story is literaly about the journey not the destination, its meant to be a character study, therefore the overall story is just a means to an end (it still has some nice twists and turns and set up a lot of interesting things to come). 30% finishing rate is above average for a game, ususaly only around 20% of ppl finish a game. I do agree they make you backtrack a little too much tough and throw one or two unecessary McGuffins your way when you are nearing the end of the journey.