X-Men Legends II: Rise of Apocalypse

To 'unlock' the character X-Man, You need to find the playable comic mission 'Age Of Apocalypse' in the 1st act of the game.

Press Up(3), Down, Right(2), Start at the store run by Forge or Beast. The sound of tech-bits will confirm correct code entry.

Press Right, Left(2), Right, Up(2), Right, Start at the review menu.

Some characters begin the game with some alternate costumes available:

Bishop: 70's costume
Colossus: Xtreme costume 2
Cyclops: Xtreme costume 2
Jean Grey: Dark Phoenix costume
Juggernaut: Original costume
Magneto: Ultimate Non-Helmet costume (starting costume without helmet)
Nightcrawler: Xtreme costume 2
Rogue: Coat costume
Scarlet Witch: 70's costume
Storm: 70's costume
Sunfire: 70's costume
Toad: Brown costume
Wolverine: Ultimate costume

Successfully complete Act 1 to unlock the following costumes:

Colossus: 70's costume
Cyclops: Original costume, 70's costume
Iceman: Snowman costume
Jean Grey: Phoenix costume, 70's costume
Nightcrawler: 70's costume
Storm: 70's costume (another one)
Wolverine: Original costume (Brown and Gold)

Successfully complete Act 2 to unlock the "Age of Apocalypse" costume for all characters that have them.

Successfully complete Act 4 to unlock the following costumes:

Colossus: Xtreme costume, Gladiator costume, Ultimate Non-Steel Skin costume (starting costume with normal skin)
Cyclops: Xtreme costume, Snowfields costume
Iceman: Non-Ice Skin (the same as in X-Men Legends)
Juggernaut: Original Non-Helmet costume
Nightcrawler: Xtreme costume
Storm: Xtreme costume, Snofields costume
Wolverine: Weapon X Experiment costume, Xtreme costume, Snowfields costume

The bonus characters already have the following costumes available:

Deadpool: Unmasked costume
Iron Man: 2099's costume, Age of Apocalypse costume
Professor X: Shadow World costume (the same from X-Men Legends)

Successfully complete the game to unlock the hard difficulty setting (enemies at level 50). You can also start a new game with your previous characters at their current experience level.

For easy leveling up, go to the Holding Pen level. There is a location where enemies keep teleporting onto the screen; it is just before the last area entrance. Note: If you stay too long without saving, your game will freeze.

In Act 2 after you rescue Beast on Mikhail's Warship, Blink will open a portal back to Avalon. Go through the portal to Avalon then immediately return to the warship. The scene of rescuing Beast will play again, and the ship will be undamaged. You can go back and get all the items again. Repeat this as many times as desired. Additionally, to get easy Techbits, health packs, energy packs, and items, return to the top of Apocalypse's tower where you fight Archangel. Smash all of the containers to get random free items. Repeat this as many times as desired.

Have Gambit and Toad on your team. Have Gambit use Prince of Thieves, and Toad use Plunder (this requires at least two extreme points). Do this when near a weapons cache and you can get about five times the amount of what you would normally get. This includes health/energy packs, and Techbits, but you still only get one special item.

First, step into the power chamber in the middle of the vault of ages. Since there is only a limited amount of time you have to use the harmonic powers, choose a faster character to do this. There is a yellow meter that will show you how much harmonic power time you have remaining. Go straight up or straight down to reach the generators. The downward path has a small maze in it. Go right instead of left. At the generator, Apocalypse will be waiting. You must beat him up before you can destroy the generator. Destroy the generator and repeat the same process with the other one. It does not have a maze, and it will be a straight shot directly to it. Just like before, Apocalypse will be waiting for you at the generator. After destroying the power of the harmonic machine, he will bring statues of the horsemen to life. You must focus your attacks on the horsemen and get them out of the way before tackling Apocalypse. When you kill the horsemen, they will return to statue form. Then, kill Apocalypse twice to complete the game. Note: Make sure you have a full load of health and energy packs before attempting this.