As expected, Castle Crashers is at its best when you've got a handful of buddies playing in the same room (four total, in this case). Taking on the campaign without companions is still sharply amusing (and completely recommended if you don't anticipate playing with friends), but the shared joy of taking in the hilarious set pieces and eliminating giant swimming felines dulls the repetition that comes naturally with beat-em-ups. Sadly, those seeking co-op partners online may struggle to do so thanks to widely reported connection issues. Between dozens of "Game is not available" messages and multiple console freezes, 1UP's experience with the online menus was overwhelmingly frustrating.
Even without functional online play for all users, Castle Crashers is zany, accessible, and memorable, and it deserves to stand among XBLA's best entries -- but until a suitable fix is released (developer The Behemoth says it is on the way), 1UP's recommendation remains tempered...if only slightly so.