Crash Bandicoot II

Hidden Warps
1. BEAR DOWN: The small ice floe at the end of the stage.

2. AIR CRASH: The 2nd river. Don't jetski, but jump on the boxes to the platform.

3. UNBEARABLE: When the cub bucks you off, go back until you see him again.

4. HANGIN' OUT: when you drop down a hole into some eel-less water, go into the foreground and drop down the hole. (Pssst....use R1 to make Crash pull up his legs.)

5. DIGGIN' IT: Near the end there is a spitter plant on a circular platform. Bellyflop onto it.

Gems:
Warp Room 1

Level Gem You Get Gem Needed for Perfect
Crash Landing None None
Turtle Woods White, Blue None
Hang Eight 2 Whites Blue
The Pits white None
Snow Go White, Red None
Crash Dash White None

Warp Room 2

Level Gem You Get Gem Needed for Perfect
Snow Biz White Red
Air Crash 2 White None
Bear It White none
Crash Crush White none
The Eel Deal White, Green none

Warp Room 3

Level Gem You Get Gem Needed for Perfect
Plant Food White, Gold None
Sewer or Later 2 White Gold
Bear Down White None
Road to Ruin 2 White None
Un-Bearable White None

Warp Room 4

Level Gem You Get Gem Needed for Perfect
Hangin' Out White None
Diggin' It 2 White None
Cold Hard Crash 2 White None
Ruination 2 White Green
Bee-Having White, Purple None

Warp Room 5

Level Gem You Get Gem Needed for Perfect
Rock It White None
Night Fight 2 White None
Pack Attack White None
Spaced Out 2 White All Colored Gems
Totally Bear White None

Bonus Warp Room

Level Gem You Get Gem Needed for Perfect
Totally Fly White None

Hints for getting gems:

To get the red gem in sno job, you have to go to crash course. When you get to the place where you get on the jet ski and there is a random floating tile up on your right. It might be at the second ski, anyway, don't get on the ski, jump from box to box and land on the platform. you will be transported to a bonus level which you should go into. After you have done that, you can get on the red gem in its two locations.

To get the green gem, you have to be in eel deal. Or the level like it, I forgot, anyway there are a couple of places where the tube splits into two parts. Once you get the boxes on the right there is a door that looks like a wall, but you can go through it. I did this when I was invinceable (3 bandicoots) but i think you can do it any time.

I cant remember where i got the other ones, but some require you getting all the apples on the level possible before you reach the platform if it is to appear.

Once you have the blue gem, go back to Hang Eight (Level 3) and repeat it until you find a huge blue gem. Stand on it and it will transport you to a secret level (that's why the first time around you probably were short a huge amount of boxes).

First level skip
In the the first level, pause the game and go to the warp room and you will skip the first level.

Free Crystal
To get a crystal in the third warp room without playing a level, go back to the first warp room and beat one of the warp tunnels. Crash will take out a crystal and toss it up but the crystal will go to the third warp room.

More Extra Lives
When you are on the 4th floor with the vortexes, get into the level with the bees. Now, instead of going underground to avoid the bees, hit all 5 of them away.(it takes practice) If done correctly, you should receive 2 lives, if done again, 1 more life will be given. Do this as much as you wish.

Secret Level
In the "UNBEARABLE" level, when the second bear falls off the bridge, go back and jump into the space where he fell. This should take you to a level with guys that shot bullets at you and a few turtles.