xbox 360-Too Human

Duplicate items
Go into a trade with a second player. Have player two put in an item or a monetary amount, then have them click the "Trade" button to highlight it, but do not accept the trade yet. Have player two press Xbox Logo, then press Y. Player two will be asked if they want to go to the Dashboard. Player two should be ready to press A on "Yes". Do not finalize the trade unless they are ready to go to the Dashboard. Once player two is ready to go to the Dashboard, finalize the trade. When player two sees the screen change, have them select "Yes" immediately. If done properly, player two will resume the game and will still have their item or bounty, as will the other player. Note: This glitch can only be done to items one at a time. Money almost has no limit.

Easy Epic items
While in Aseir, preferably in Co-op mode, go to the mission selection screen, and choose mission 3-4. Go through this mission until you reach a bridge with two enemies you must kill. After this, you will go through one more door where you will kill a troll, a spider, and then another troll. At the location of the last troll, there will be a door in front of you and a pathway to your left which leads to a well. From here, walk through the door, and have another player stand by the pathway. Walk through and kill all the enemies, including the spider. Once they are all dead, have the other player walk across the path towards the hallucination well. Doing this will respawn you back to the path where your friend is located. You may go through the door once more to kill all the enemies. You can do this as many times as desired. To do this while not in Co-op mode, follow all the steps previously described, except you must stand in front of the door so it stays open. You must then shoot all the enemies including the spider. Once they are all dead, go to the exact pathway previously described. You will return to the door, and all enemies will respawn. Doing this long enough will result in an Epic item. Note: After doing this many times, if the spider does not drop any Epic or Red items, return to Asier to reset the random drop generator to give you a better chance of finding those items.

Easy "Show No Mercy" achievement
Find a group of 25 or more enemies, use "Fenrir Bite", and use your Battle Cry. "Fenrir Bite" will keep your multiplier up, which keeps your Battle Cry going. All you have to do is kill all the enemies to get the achievement.

Hidden characters (demo version)
To unlock the Berserker and Commando character in the demo version, make sure that you are not logged onto Xbox Live. Change the year in your system settings to 2009. This will automatically unlock the extra two characters for you to play in the demo. Note: If you are logged onto Xbox Live, the service will automatically update the date and time on your machine, and this trick will not work.

Achievements
Accomplish the indicated achievement to get the corresponding number of Gamerscore points:

In the NORN's Favor (10 points): Find and activate all available Cyberspace wells.
Chosen of the Aesir (20 points): Achieve Adept status.
Elite Warrior of the Aesir (25 points): Achieve Skilled status.
Hero to the Aesir (30 points): Achieve Hero status.
Legend of the Aesir (30 points): Achieve Legend status.
True Son of Odin (40 points): Achieve God status.
Jack of all Trades (10 points): Achieve Adept status or greater for all classes.
First Step toward Destiny (5 points): Assign your first skill point.
Path of Ruin (25 points): Defeat 100 total enemies using Ruiners.
Unrelenting Rage (10 points): Achieve a 100 hit combo.
Show No Mercy (10 points): Defeat 25 enemies with a single Battle Cry.
Rune Lore (10 points): Collect 1,000 Runes.
Relics of a Forgotten Past (5 points): Complete a 7 piece Elite armor suit.
I'm Rich... (10 points): Collect 1,000,000 in bounty.
Artisan to the Aesir (10 points): Construct 100 blueprints.
Aesir Ascendant (10 points): Complete a tier 3 charm.
Fenrir's Bite (10 points): Assign a skill point to a sentient ability.
Display of Power (5 points): Execute either a 2 in1 Juggle, Ruiner, Finisher, Slide, or Gunfire move.
The Final Strike (10 points): Kill 100 enemies with finishers.
Death from Above (10 points): Kill 100 enemies with air combat.
A Valorous Deed (5 points): Defeat a polarity enemy.
Without Equal (10 points): Defeat 1000 polarity enemies.
Relics of Ascendance (10 points): Complete 20 Charm Quests.
Archivist to the Aesir (10 points): Acquire 7,500 item drops.
One God Enters, One God Leaves... (20 points): Complete 3 Secret Arena Battles.
Serve Em Up (10 points): Juggle an enemy to be killed in air combat by a teammate.
Teamwork Takedown (10 points): One player must destroy the troll's chest armor and the other must mount kill.
Blooded of the Aesir (10 points): Achieve Novice status (Level 5).
Hate for the Machine... (15 points): Kill 20,000 enemies.
Additionally, there are 21 secret achievements:

Through the Halls (80 points): Hall of Heroes has been completed (all tokens collected) in Single Player or Online Co-op Play.
Frozen Vengeance (80 points): Ice Forest has been completed (all tokens collected) in Single Player or Online Co-op Play.
The One That Got Away... (80 points): World Serpent has been completed (all tokens collected) in Single Player or Online Co-op Play.
To Hel and Back (80 points): Helheim has been completed (all tokens collected) in Single Player or Online Co-op Play.
Unstoppable: Hall of Heroes (10 points): Hall of Heroes has been completed without dying.
Unstoppable: World Serpent (15 points): The World Serpent has been completed without dying.
Unstoppable: Ice Forest (15 points): The Ice Forest has been completed without dying.
Unstoppable: Helheim (20 points): Helheim has been completed without dying.
Force to be Reckoned With (5 points): 100 Elite enemies annihilated.
Avenger of the Slain (30 points): 1,000 Undead slain.
Bane to Goblins (30 points): 2,500 Goblins defeated.
Hunter of Elfkin (30 points): 500 Dark Elves vanquished.
Slayer of Trollkind (30 points): 50 Trolls destroyed by mounting.
Exultation of Steel (30 points): Hel has been defeated by the Cybernetic Baldur.
Triumph of Humanity (30 points): Hel has been defeated by the Human Baldur.
The Blood of Heralds (10 points): 100 enemy leaders conquered.
Feeder of Ravens (10 points): Kill 10,000 enemies.
NORN Novice (5 points): First Cyberspace Well has been activated.
The Call of Battle (5 points): First Battle Cry unlocked.
Trial of Ascendance (5 points): Complete a level 1 charm.
Valkyrie's Folly (5 points): Die 100 times.