Castle Crashers

Collect every animal orb (pet) in the base game. Some are bought from the in-game shops for gold, others are hidden in levels - break objects with bombs or dig up the X-marked spots with the shovel to find them. They carry across playthroughs, so you don't need them all in one run.

Win 40 online Arena matches. Pure grind - host or join public Arena games and rack up wins; the Archery arena is often faster as fewer people pick it. Wins accumulate over time, so chip away at it.

Get from Home Castle through the Barbarian Boss areas without your character landing a single hit on anything. Far and away easiest in co-op: a second player kills everything while you just move and dodge along.

Ride through the Abandoned Mill (an auto-scroll section) on a deer without hitting a single obstacle. With fewer than four players there are riderless AI deer about - just follow one, as the AI deer automatically weave around every obstacle and lead you a clean path.

In a multiplayer game, win the end-of-level duel (be the last one standing) to claim the kiss from each of the four princesses - freed after the Barbarian Boss, Cyclops' Fortress, Ice Castle and the Final Battle. You have to win the duel yourself, and it won't count if the others are already dead when the princess is freed. Kisses carry across sessions.

On the Flowery Field level, step into the catapult to load your knight, then wait and launch exactly when the power meter fills completely. Releasing at full meter is the whole trick.

In a four-player game, revive each of your three fallen teammates at least once. Let enemies knock players down and take turns reviving one another until you've personally resuscitated all three.

Defeat any level's end boss using only physical attacks - never cast magic. Quickest on the first boss, the Barbarian Boss: just don't touch the magic button for the whole fight.

Survive until the 2:30 mark in the Back Off Barbarian minigame, dodging the pursuing barbarians on the grid by tapping the face buttons to move without getting caught.

Beat a boss while playing as one of that boss's own minions. Easiest route: unlock the playable Barbarian by clearing the Barbarian Arena (survive all ten waves), then start a game as the Barbarian and kill the Barbarian Boss. Other pairings work too (Snakey vs Medusa, Iceskimo vs the Frost King).

Complete the full campaign - beat the final boss - with any single character. No special conditions, just reach the end once.

Equip a shovel and dig up ten buried items at the "X" marks on the ground in various levels. Digs accumulate across playthroughs, so no need to get all ten in one run.