When you go down the first latter, jump up while the screen is going down. You will end up inbetween the floor. You can now go through the floor and be invincible, but can not complete the level.
Go through anything
Have Giga Crush full with Mega Man, then go to any level with ladders. Climb on one of the ladders and stay there, then use the Giga Crush and you will go through anything you want, but careful not to fall down straight or you will die.
How to get all the weapons
At the title screen press up, down, up, select, a, b, up. You should hear a sound. That means you have all the weapons.
How to use the Giga Crush
Enter the menu and select the giga crush then a meter will apppear as if a normal power then take damage until the bar is fill the wait and use it when near the enemy.
Revisit Intro Level (Xtreme Mode Only)
Reach the fourth and final Sigma Stage on Xtreme Mode (Fourth Sigma Stage is not accessible in other difficulties). Lose your last life and get a Game Over to any of the eight Maverick bosses in the teleporter room. Choose to return to the Stage Select screen on the Game Over menu. Enter the actual level of the Maverick boss you just lost to. Reach the boss room. Instead of leaving the level, you will be warped to the intro level of the game with all of the weapons and upgrades you've accumulated. Beating the intro level will return you to the Stage Select screen as normal.
X Upgrade Locations
Neon Tiger stage: when you see the capsule simply use the flame mammoth´s power and burn the part of wood below then simply enter.
Launch Octopus stage: simply go down every time you can just before going up the ladder verify that you can go ahead in one will be a capsule where the Giga Crush is.
Bolt Catfish stage : when going out of the part water is flowing down stick to a wall and keep going up then left and get the leg upgrade.
Flame Mammoth stage:in the part crates are above you simply crush them with you r head go up get the arm upgradde and come down then jump to the conveyor belt then jump to the wall till the top then crush the crates to get an energy tank.
Zero Upgrade Locations
Foot part Wire Sponge stage: in the first "elevator part" do not take it instead let it pass and jump through the hole quickly attach to the wall at the right you will see a space at the left enter and get the foot upgrade.
Head Upgrade Overdrive Ostrich stage: after passing through the tornado part there is a part where you look instead of just falling do an air-dash and you will fall in a stair climb them to get to the head upgrade.
Arm Upgrade Tunnel Rhino stage: when in the part using the robot fall down to where the mavericks are but instead of right go left at the end you will see two crates get down of the robot and use the lighting power to destroy them and you will get the zero final.
Body Upgrade Blast Hornet stage:after passing through the part of the moving platforms dont destryo the enemies if you do the floor will fall down keep on going until the end jump and use the tunnel rhino power in the wall it will be destroyed revealing a secret room enter and get the body upgrade.