Your demise, provided you're playing with more than just yourself, will reincarnate you in a skeleton form, where you throw bones at enemies and await revival from another player. Every time you die as a skeleton you'll come back as another, but you'll be docked five minutes from the timer – fail to kill the boss before a half an hour timer hits zero and you'll all be kicked back to the title screen.
Understanding your character's loadout is essential, then, and it doesn't take too long to work out the best characters in the pack. Jonathan and Charlotte basically work as a pair, so you'll probably not be inclined to bother with them and instead focus on somebody that can function without requiring another human being to assist. Essentially it boils down to the magical Shanoa or weapon-loving Alucard, and if you take the game for a spin online you'll see far more of these characters than any of the others.
Instead of focusing on the individual talents of each character, bringing out the best of their unique abilities, Konami goes the other way and creates parity by dialling everyone's skill set back to basic levels. Soma might be able to use his soul-absorbing abilities to pick up magic spells, for instance, but when it comes to weapons and equipment he's basically in the same boat as everyone else. There's no solid levelling system, and while there's plenty of equipment to boost your stats it happens to be doled out in giant and boring swathes rather than gentle, incentivising increments – unless you're lucky enough to pick up something decent from a random drop, that is.
It can be addictive: never underestimate the power of The Grind. But that doesn't necessarily mean it's been competently crafted, and the inelegant loot and shop system means you're left with the bare minimum of incentives to progress. It's always nice to get new equipment, of course, but the equipment selection is just too sparse. Getting new magic spells is more exciting, but there's also a random element to it which can be hugely frustrating.
There's also a big problem with the speed – you're capped at the most basic of walking speeds. While other Castlevania games hit their stride after giving you the ability to significantly boost your momentum, Harmony of Despair forgoes such a perk to ensure everyone feels like they're permanently wading knee-deep through a river of golden syrup. As you're required to plod through stages repeatedly – either by getting yourself killed or for The Grind – there's a certain resentment that steadily grows as your little sprite chugs about.
The idea is that it's supposed to feel like conquering a mountain, but in reality it's more like that annoying hill you've got to walk every day on the way to work. Harmony of Despair tries to hop onboard the contemporary co-op bandwagon, but in doing so it sacrifices almost everything that makes the series good to begin with. The game's main claim to fame is that it's trading on the series' former glories, so you might as well just play Super Castlevania IV or Symphony of the Night instead.