This game has a run page on SDA!

General speed tips

• Focus run everywhere. There's no excuse not to.
• Make "Open Palm" decisions at the end of the game. You will spare yourself from fighting extra fights.
• Remember that both the Start and A buttons can be used to skip dialogue.
• Whenever the game asks you if you want to skip a flight session, remember that the default is always "no." So don't waste time making sure you're going to skip the flight.
• Remember that loading screens count against your time.

Combat

• Fights will be quicker if you press [A A], [A A], [A A] instead of [A A A], [A A A]. Hopefully that made sense.
• Switch back and forth constantly between two or three styles. This will pin enemies down.
• Switching to a demon will remove all adverse effects (Disoriented, Immolated, etc.) but it takes lots of time, so try your hardest not to get burnt or whatever!
• Don't forget Harmonic Combos! Ice Shard + Your Favorite Martial Style on Lost Spirits works great most of the time.

Use the sword!

• Use Fortune's Favorite instead of Golden Star. The sword can hit many enemies simultaneously, and your enemies don't go flying if you use a power attack.
• In some places, especially the beginning of the game, you can get some insta-kills if the sword just barely scratches an enemy. Try it out, it's weird.
• [PC only] The 2nd upgrade for the sword is for free, so get it! It's in the field when you're first dead, behind you (iirc).

Followers

• Keep your followers in support mode, for the most part. Most of the time, your followers will spend forever "fighting" enemies way on the other side of the battleground.

Sequence breaks

There are a couple of opportunities where a sequence break can be performed. Essentially, you're pausing, saving and reloading at a time and place that you're not supposed to. Here are all the places that have been tested to work:

• While talking to Forest Shadow, immediately after she says "A woman in blue? ..." and immediately before the "oh-God-here-comes-the-Water-Dragon" sequence. (Go to 12:46 in Segment 3 of the current speedrun.)

Here are some places that still need to be tested:

• Upon defeating the Emperor, immediately after Master Li approaches the throne and the statue crumbles, and immediately before the music starts. (Check out 1:50 in Segment 9 of the current run.)

Specific numbers

• On the Xbox, a loading screen lasts an average 30 seconds.
• Buying Storm Dragon from Spear Catches Leaf in the Forest costs 4,500 silver.
• Skipping the fight with the Lotus Assassin Slave Drivers requires 40 Intuition.
• Skipping the fight with Death's Hand the second time requires 70 Intuition.

Camera skip?

In the Necropolis, you can skip some fights by rotating the camera away from where the fight is supposed to take place. Watch what happens at 12:06 and 12:15 in Segment 6 of the current run. The theory is that you can apply this trick to other fights in the game. So far, no other places have been proven to work.

Glitches

As far as we know, no one has discovered any useful "major" glitches -- meaning, those on the scale of skipping significant parts of the game. This holds true for the Xbox release; I really don't know about the PC version. The PC version might be easier to exploit because there are more characters/features/stuff in general to play with. On the other hand, it was supposed to be the ultimate bug fix for the Xbox version.

GameFAQs lists one sortof useful glitch (here). The only problem is that there are very few opportunities in the game to use this.

Instant Kill for Battles With Cutscenes

This glitch will instantly and completely kill whatever enemy you face if a cutscene is known to occur in the middle of the battle. To achieve this you must have a transformation style in your hot keys for styles. Then right before the cutscene is known to occur, transform. During the cutscene, you will notice that you have changed back to your normal form, but are blinking oddly. When you enter battle again, you will slide along the floor without walking, and will not be able to attack. Now use the transformation style again and the enemy will die, instantly.