As you defeat enemies and smash objects, different colored gems called Crystals appear. Grab as many crystals as possible and them to buy upgrades.
You'll need to unlock the wall-smashing special move to get to some of the hidden lore objects.
Watch out for bats and other flying enemies - they're a lot trickier to hit than ground-based foes.
Power Of Grayskull And Summon Tokens are a great means to yout battle.
Don't waste your Grayskull powers. They make you all but invincible, but they're not cheap, so use them wisely.
Break stone pillars and platforms not only will you receive Crystals for your efforts, but debris also damages nearby enemies.
Collect as many as you can Lore Tokens. They unlock bonuses, like character bios, comic book covers and concept art.