Fun is in the Eye of the Beholder
Castlevania: Harmony of Despair (hereafter "HoD") is a fascinating core idea plagued by a dozen design decisions that stop it from being something truly great. It is the rare XBLA release that still has a solid multiplayer community some time after release (more than half a year at the time of this review), offering a rare combination of 2D sidescrolling, loot grinding, and speed running that makes it difficult to categorize. Think Diablo, except with the core play mechanics that prove demanding for reasons beyond merely having the wrong/inadequate gear setup and moving into tightly controlled platforming. For a particular type of gamer, who loves replaying stages to find better gear or improve his or her own personal playing skills, this game offers nearly bottomless replay. If you are not that particular sort of person, HoD represents nothing short of tedium.
Before the stage begins, you pick a character (the core game comes with five protagonists from prior games - Alucard, Soma Cruz, Jonathan Morris, Charlotte Belnades, and Shanoa - while a number of others can be purchased as DLC), and set up your character's equipment and attacks. Like any good loot game there's a wide range of possible gear to find in stages including weapons and armor, spells, special attacks, food, and accessories. Each character has his or her own list of valid gear (though there is substantial overlap between similar characters), and can only find gear he or she can equip. While the roster is enormous once all's said and done, characters of the same general archetype (whip-using hunter, magic-using witch, monster who's not so bad after all) are similar enough that there really isn't much compelling reason to play using more than one character of that type. Getting a single character to their absolute maximum potential (involving random loot drops from boss monsters, finding very specific souls or magic spells, or using a given subweapon repeatedly to power it up) requires dozens of hours of play. Once again, if you are the sort of person who just loves driving up numbers, then this one will keep you going for a long time. For everyone else, expect to be thoroughly outclassed by more advanced players.
HoD supports up to six player simultaneous cooperative play, and multiplayer is identical to single player except that there are more of you running around and enemies scale up in power accordingly. Except for very unusual circumstances, you'll always want to be playing with a team. The chaos of a sidescroller is somehow much more fun with more people trying desperately to dodge fireballs and swinging guillotines, and the different types of characters all complement each other in interesting ways that allow you to pull off unusual maneuvers or reach locations you would be unable to reach alone.
Ultimately, this type of game hinges entirely on the community. You'll find the HoD community a double-edged sword. On the whole the community is large and friendly toward new players. You'll rarely find yourself kicked from the team for being undergeared, though much of that may rest on there being no way to check another player's status short of how they actually perform in the game. In short though, you'll find games rather dull if you play with people significantly more powerful than you are. Beyond mere damage, they can run faster, jump farther, and have a wider array of moves that will leave you in the dust. All you can do is follow the trail of corpses to the boss room in the hopes of getting there before they fell the beast within. The plus side is that everyone gets a drop from each chest that the party opens including the golden chest the boss leaves behind. Skills that require use to improve won't go any higher, but at least you'll have a chance at pulling some gear upgrades from such teams.
HoD is a lot of fun if you have the patience to get over the initial hurdles and are willing to accept being a dead weight for a while. There is a really interesting core idea here, and it's clear to this writer that Konami could make something really special next time if they put some proper development muscle behind it. For now, if you like difficult sidescrolling and playing stages over and over again in the hopes of improving your performance and getting better swords, welcome home. If that doesn't sound great to you, then HoD really has nothing to offer you.
