All Weapons at the Beginning
While at the beginning of the game, you can obtain everything easier than jumping to the cliff side. Go to a platform that has a nuke weapon and a green bush on top( It no the one near the lava). Jump on the platform, then the greenbush, then double jump. You will obtain full health, the barrier, full jet fuel, 999 shots for all weapons, but not the eggs.
Free Ride
Ever had trouble getting through areas with lots of dinosaurs without losing half of your life? Here's a tip that will get you through.
NOTE: You need to be a very accurate jumper to achieve this feat.
Find a T-Rex, Low-flying Pterodactyl, or a Tricerotops. Jump onto their back, but stay away from the head. If you land in the middle of their back, you can ride them. However, if you land on their head, you will lose life. You can't achieve this trick with the spitters or the Stegasauruses.
Free Shield
When you encounter a low-flying pterodactyl about to dive at you, jump on its back. If you succeed in doing this, wait until you go really high and you will get a shield. To get off, just jump.
All Weapons at the Beginning...