Mission 1: Hidden Red Orbs:
Go to the part at the beginning where you double jump over the rubble blocking the way ahead. Face the statue and double jump to the statue's shoulder, then again to his head. Once on his head, at many Red Orbs will fall.

Mission 1: Unlimited Red Orbs:
Get the first Red Orb at the beginning then keep restarting the mission.

Mission 1: Unlimited Yellow Orbs:
After completing either character's game at least once and have unlocked the "Mission Select" option, go to mission 1 and collect the Yellow Orbs. Save the game and quit. You may now continue where you left off. This trick is useful when facing the tougher Bosses on the harder settings.

Mission 2: Hidden areas:
Enter one of the rooms that has a coffin and bones in it. Go up to the coffin and press Circle. This will take you to a hidden room full of enemies and some Red Orbs.

There are actually two secret areas in mission 2. Both are in separate rooms where skeleton coffins are located. Check every coffin you see to find them.

Mission 3: Hidden area:
Before or after the cargo elevator trip, you will reach a door located between two other doors with just a couple of stair steps. Stand in front of the door on the left side of the screen and press Circle to enter a secret room.

Mission 4: Hidden area:
When you start, look for the first door on your left. It is not very big and is sticking out slightly. Approach it and press Circle. It will lead to a secret area where big flying creatures attack you.

Mission 5: Hidden area:
When you enter the barricaded area, go to Dante's left and fall off the cliff. There are several medium Red Orbs. Follow that until the end. There will be an Orb Dispenser. Go just to the left of the Orb Dispenser to find a garage-type door. Press Circle, and there will be plenty of Homromsira in there.

Mission 6: Defeating the "head":
When you are fighting the "head", not when it is the full body, when it falls on the ground and starts shooting lasers, wait for them to stop. You will have a few seconds before it will go into the air again. In that time, run up to it and hit it with your sword on the open mouth. It will do double or triple the damage.

When the head floats down to the ground and shoots its lasers, press Circle to flip Dante around to the back of the head. Slash the monster while it is shooting the lasers. After it is done, using the sword will help Dante's Devil Trigger to fill up. When it is full, it will do even more damage.

Mission 7: Hidden area:
At the very end of the mission, before entering the door that leads to the roof, press Circle at the door to the left.

Mission 8: Easy Red Orbs:
The level select option must first be unlocked for this trick .Select level 8. Fight and defeat the opponent as quickly as possible without using items. You will get about 4,000 Red Orbs if you get a "B" rank.

Mission 10: Hidden area:
After defeating the giant butterfly and the larvae, you will go down a set of stairs. After the game loads, go to the first set of doors you see and press Circle to enter another hidden room.

Mission 14: Hidden area:
When you start the mission, turn around and press Circle against the door on the left. You should enter a secret room with enemies to fight.

Mission 16: Hidden area:
On this mission, you will enter a room where you will find the item named Sacrilege. Get the item to make the energy balls stop coming at you. Then, on the floor directly under the balcony where the item was located, there will be a wall that resembles a door. Press Circle in front of that wall and it will open a secret room.

Mission 16: Easy Red Orbs:
When you pass mission 16, you can get as many red orbs as desired. Go up and down the elevator, killing all enemies. Remember to mix up your attacks to increase your stylish bonus. Do not use a maxed-out weapon, as this will kill enemies too quickly and not allow you to get your stylish up fast enough. If done correctly, you can get up to 2,500 Red Orbs on each trip up and down the elevator. This may get tedious, but is well worth it when you get to the "Must Die" modes. Save your data when you have the desired number of orbs.

Mission 18: Easy Red Orbs:
Complete the game as Dante. Go to Mission 1 and grab the Gold Orb, then go to Mission 18 to defeat Argosax the chaos and despair embodied. Repeat this as many times as desired.