After beating Cortex go back to the previous levels.Get all gems and get all GOLD relics to play the secertlevel with mutated bosses.
heres how to get the blue red and green gems
BLUE:defeat tiny to get death tornado than go to the level ruined when you get to the nitro swich crate jump on top of it and double jump to your left than glide(death tornado spin) in mid air to some iron crates keep going to your left on the iron crate path till you reach a iron bounce crate bounce on it to get the gem(snow crash secret route will be unlocked)
GREEN:go to sunken city and reach the first '!' crate than go past the start to reach a iron crate shield hit the tnt to create a hole in the shield go down this hole to collect the gem.I recomend to not hit the first checkpoint until you get the gem so that you will keep the gem when you die.(just hangin secret route will be unlocked.you double jump past the end teleporter to find it)
RED: find the nitro swich crate on star to the finish BUT DONT HIT THE'!' CRATE TO ACTIVATE A METAL CRATE BRIGE.just hit the nitro swich crate and fall in the hole be careful not to fall off the metal crates than continue to you right until you reach the red gem.(red gem path on temple of boom will be activated to find when you jump over a hole when you land you will notice stairs continue down that path till you find the platform)
When you beat Dingodile,go to the bottom of the screen to get the body slam power
Defeat N.Gim to get the double jump power
Okay first beat Tiny, then go to any level with a big leap; I suggest one of the space levels in Cortexes levels like the first one.
Double jump and then rapidly press the B button; you have to ensure you press it quickly or this will not work. If you can't do this trick at first - keep trying. Do not give up.
When playing Crash Bandicoot the huge adventure, pay close attention to the names of the levels. Sometimes they give you hints to some secrets.
For example.... The level 'Temple of boom' sounds a lot like 'Temple of Doom'....As in "Indiana Jones and The Temple of Doom". A key movie point is the temple itself, in which a secret area was hidden under the temple. likewise, in temple of boom, there is also a secret area underneath the temple, leading to the red gem path.
Many other levels also have cool things inside that are based on the name.
To get platinums on Time Trial, do the following on levels:
Use running shoes.
Beat the secret level to run faster and to change more boxes into time boxes.
Hit all time boxes.
At the start run back and forth 4 times to build up to maximum speed then hit the clock.
Tornado spin over gaps and double jump up higher ledges.
Defeat Tiny the Tiger,then go to the bottom platform to get the Tornado Spin Power.
Defeat Cortex,with one of the powers,to get the Turbo Run Power