These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Dante's Inferno
Demonic Spiders: Heretical Priests, which have the nasty habit of rendering themselves and anyone around them cross-proof (but not magic-proof!) until the Priest dies. On their own, they can be handled relatively easily, but they get really annoying when they use their protection on angered spirits, shades that catch fire and can only be attacked by using the cross attack (or holy magic) to put out the flame.
Designated Villain: The first three bosses. Death is... well, Death, Charon is just there to move souls, and King Minos only sorts the souls into the proper circles. Not terribly glaring, though; no one likes Death when he visits, the other two "work" for Hell regardless, and all three got in Dante's way.
Disappointing Last Level: Many reviewers have praised the game's first several levels, but have stated that the later levels fall into this. That is, Malbolge is just a series of trials and Cocytus is nothing but the Final Battle.
Dude, Not Funny!: This game is one of the reasons EA is well known for intentionally controversial marketing ploys. Aside from the "Sin to Win" contest that required entrants to harass booth babes, there's also the fake protestors they hired to picket in front of EA headquarters. Neither are very well regarded nowadays.
To elaborate on this, upgrading the cross unlocks new holy spells which you can purchase. One of these is Divine Armor, which not only renders Dante invulnerable, but upgrading this spell causes Dante to recover health persistently while Divine Armor's invulnerability is active. Upgrading it fully increases this regeneration rate. Combine with Ciacco's Bile, a relic that causes persistent mana regeneration, and Divine Armor will literally be the only spell you ever cast all game, and the only time you will ever die is if you fall off something or (somehow) run out of mana. Possibly averted by the fact that if you do this and neglect the scythe, the final boss will curbstomp you.
At (almost) the top of the other side of the upgrade path, you get the passive ability to regain mana... By killing things. that's right, the game lets you go invincible, regain health while doing so, then regain mana by killing the enemies you can't be touched by.
The fully charged blast of the cross comes to mind. It is very powerful, has a long range and area of effect, breaks all defenses and knocks the enemy over. The only downside is of course a charge-time, which isn't very long. Furthermore, with upgrades, you can make the cross attack even stronger, and regain health from every enemy that dies from a cross attack. Single enemies (even some bosses) can just be spammed to death by it and even groups can be reduced to dust pretty quickly if you let them hug together on a tight area.
This, however, makes sense. Demons hate crosses, and the cross belongs to Beatrice, who is a symbol of purity and innocence.
Goddamned Bats: The Pests and the Temptresses, with the latter verging on Demonic Spiders on "Zealot" and reaching that territory easily on "Hellish".
Nausea Fuel: Gluttony. Nothing quite as disturbing as walking though a giant digestive system. Or, for that matter, the Gluttons themselves explosively crapping excrement on you.
Rated M for Money: Somewhat subverted as this was meant to be a realistic depictions of what hell is said to be like. Which would be horrifying and filled with nudity (especially in lust) and violence, not to mention people only go there for one reason. While it did change the basic story of what the book was about, it was pretty faithful to its core message of redemption and ends on a peaceful note.
That One Level: One or two of the bolgia (sub-sections of hell) of the Malebolge.
Squick: Even the most hardcore gamer is going to wince at some of the stuff they witness in some of the circles. Like most of the stuff in the "Lust" and "Gluttony" levels.
Values Dissonance: Remaining relatively true to the source material, Dante's former mentor is in Hell for being a homosexual who engaged in sodomy. The dissonance may be why you earn an achievement for absolving him.
This may not be that bad, as some speculate Dante's mentor is actually in Hell for being an unrepentant child molester (a more reasonable excuse to place someone in Hell). Either way though, there will be dissonance. If you believe the mentor is in Hell for being gay then you'll at least have a nice Achievement to be gained by sending him to Heaven via absolution. If you believe the mentor is in Hell for pederasty, then getting an Achievement for sending him to Heaven may feel like a slap to the face.