Unlockable: Hell Mode
To unlock Hell Mode (which is a more difficult version of the regular game), beat the game on normal mode
Hint: Gauge Building
Building up the orange gauge on the bottom of the screen is important if you want to unlock new combos and other in-game unlockables that are otherwise inaccessible. However, it may not be clear on just how to do so.
Using Nariko, try to score consecutive hits on enemies to build the number on the left side of the gauge up as much as possible. If Nariko is injured or waits too long in between scoring successful hits, the number will reset (though the progress made on the gauge will remain). With Kai, you must score consecutive hits as well, though building up the gauge is made considerably easier because her time constraints between hits are much more lax, and her use of aftertouch (when shooting arrows) allows you to guide the arrow to its intended target.
Hint: Health Jars
Health jars strewn throughout the game have an obvious use, since they will fully heal Nariko or Kai if they are injured. But they are also great supplements to filling your gauge up. Try to work in a health jar into some combos, since it will give you extra points towards building up the meter while healing you simultaneously.
Hint: Revisiting Stages
You can revisit any stage in the game once beaten, as you already likely know. This is a great way to seek out a full gauge on any stage you hadn’t yet achieved on one. What’s more, any emblem you’ve managed to unlock (there are three on each stage) will remain unlocked, as long as you successfully get through the stage. However, you must build the meter up from scratch if you want to unlock any emblem you’ve yet to get on any stage, regardless if one or two are already unlocked.
Hint: Turn Off Sixaxis
If you want an overall easier experience with Heavenly Sword without any clunky Sixaxis use, you can turn all Sixaxis features off in your options menu
Hint: Points with Kai
Whenever you’re controlling Kai and are going for points (and hence a full gauge), you can score more points by attempting multiple hits on each of your foes. Body shots are only worth six points, while other non-head shots are worth eight points. Headshots are worth nine points. So, try to hit a soldier in the legs to knock him down, scoring eight points, and then score a headshot to get another nine points (for seventeen total). Scoring headshots right off the bat will actually take points away from you. Then again, some can be shot again when they’re dying on the ground for additional points
Easter Egg: Kratos’ Gear
When you head to the armory, look around at the different trophy cases. One of them contains Kratos’ armor and swords from fellow Sony series God of War.