Welcome to Gaia! ::

Run up the stone path after all the cut-scenes. Grab the Yellow Orb nearby. Jump into the high up walkway for a blue orb. At the end of the path, you should see a hole you should enter. Enter the hole and you are in the Main Hall.

There is a giant monument of Mundus, the final boss of the game. To continue, you must collect 45 Red Orbs that are scattered throughout the entire room. There is also a blue orb you can jump to. Head up the staircase and grab Red Orbs in spaces you cannot yet see. Practice your jumping ability while doing so. You'll see a Statue of Time, but as of now, it is inactive.

Once you have collected 45 Red Orbs, run to the door with those skeleton faces. Pay them 45 Red Orbs and then the door will open. Go through the door.

A gate is nearby - the exit to this damn castle. Unfortunately, the gate is lowered and Dante will need an item to open it. Nearby are knight statues. Slash them for Red Orbs. Whenever you see tables, knight statues or other things that seem to stand out from the background, slash them. They usually contain Red Orbs. Some may even reveal some useful weapons!

Head through the next set of doors. In this room, climb the staircase. Head through the hole at the top and look at the Marionette for a Rusty Key. Take it back to the Main Hall and unlock the blue doors. Marionettes attack, so slash them up with your Force Edge. Down the staircase, go to a room that is blue, on the second floor. Look in the water on the left for a Blue Orb Fragment.

Travel back to the Main Hall. There, unlock the blue doors and pass through them. Dante is now in a room with a giant plane. The red doors nearby are locked, but slash some tables up for prizes. Look in the corner for some round shield and slash it with your Force Edge Sword. Once the rune symbols are fully lit, ride the elevator below Dante's feet down.

In this arena, destroy all the Marionettes. Legions of them will attack Dante, but they will pose little threat if you Jump and Slash down and slow them down with your Handguns. Once they are all dead, ride the elevator back up to the airplane room. Back there, kill the now-live Marionettes. This shouldn't be difficult. After they all die, the red doors nearby unlock.

If the tense music stops but the door is still locked, there is a Marionette somewhere in the room that is alive. Find it and kill it. Head through the red doors to end the first mission!

Hey Dante no need to be that "kind" ok? This guide is for people who are starting to play the game or maybe got stuck while trying to solve a puzzle, I needed help aswell the first time i played it so be kind (:
By the way really nice guide boss ! =D