Well... It had me occupied for 15 minutes...
On a positive note, you are able to summon upgradeable creatures called legions to battle alongside you, although doing so lessens your own attack power. The different legions slice, smack, explode on, or shoot arrows at enemies, and they acquire special attacks as they gain experience. Things would've been better if the most powerful legion didn't get blown up five minutes into the game, though. Besides not portending well for the futures of the other, lesser legions, this one's vanquishment forces you to collect his scattered remains from various stages before you can use him again. You also lose all the legions during the most boring stage, in which you become a sidekick chick who jumps around and fires pistols while marching like she's got gum stuck to the soles of her shoes.
Capcom has an arsenal of high-quality survival-horror console games such as Devil May Cry and the Onimusha series from which to create PC ports; why the company chose to port Chaos Legion instead is mystifying, but gamers might have been better off if its discs had stayed forever unplayable.