Rules the game never explains
Why does Rex keep restarting at the beginning of the stage?
Because a Tiki Torch becomes a checkpoint only after Rex breathes fire on it. Leave the torches unlit and every lost life sends him back to the start of the world. Light each one you pass, even at full health: Rex can take plenty of hits, but spikes and lava pits kill him outright whatever his health bar says.
What each fossil does
Fire Fossils show a flame. Each one makes Rex's breath reach farther, and with enough of them the flame can finish enemies off without a kick. The Fireball Fossil, with a flame in flight, swaps the stream for fireballs that fly ahead until the next time something hits Rex, so dodge carefully while you have it. Roar Fossils, the plates with four stripes, feed the meter for the roar (Up+A), which hits every enemy on screen at once. Both meters start over at the beginning of each stage, and losing a life can also cut the flame back to its starting length.
A Heart Fossil refills Rex's health completely, Rex Chances adds a life, and an Air Bubble Fossil gives him more air underwater. The Invincibility Fossil lasts five seconds, enough to get past one enemy. A Pterosaur Ptaxi calls a pterosaur that carries Rex along a set path to higher ground.
Can Rex get off the skateboard and keep it?
No. Once he ditches it with B, the board is gone until he finds another one. It doubles as a weapon, though, so aim Rex at an enemy before you press the button. When the board gives him a lift but gets in the way of the landing, ditch it in mid-air. Sometimes that is the only way onto solid ground.
Leapsnakes and Sucker Fish
If a Leapsnake swallows Rex, breathe fire. Underwater, keep clear of Sucker Fish: get too close and one sucks the air out of Rex, the opposite of the friendly fish that hand some over.
Hidden lives and shortcuts
The first five worlds
In Jungle Jam, crouch in front of the head and scorch it, or skip it entirely by bouncing over it from the spring. Swamp City hides a spare life: keep jumping inside the second pipe from the start, and with luck one turns up. Further on, past the bee, sits a platform that looks too high. Climb the slope, take a run-up and jump from the spot marked by a branch. Leave the turtle alive, because it is the step Rex needs to climb higher.
The worms in Inner Works scatter if you press left and right in turn, and the bubbles are easier to avoid than to kill. In Dino Graveyard, climb into the mouth of a dead dinosaur and Rex falls down, collecting prizes on the way. Skriitch's Forest deserves a proper look before the boss: the mushrooms work as springs, and at the very top a bird waits to fly Rex to an extra life.
The way back
Skriitch's Forest 2 is generous with lives. At the three pits, drop into the two outer ones first and the middle one last, which opens a room of prizes with extra lives among them. Another life sits under the tree next to the torch. A Pterodactyl here circles overhead dropping rocks, and the way past it is to find the lowest point and duck.
Dino Graveyard 2 has a shortcut. Three creatures give Rex rides, two heading right and one left; take the upper right one and it carries him to a dead dinosaur's mouth. Jump in and you're at the boss. In Swamp City 2, take the right-hand pipe where the path forks, since it holds more prizes.
How to win a continue in the bonus stage
Collect at least 80 eggs in a single stage and a bonus stage follows once you clear it. The count starts over every stage, and the last stage has no bonus at all. Each bonus is an overhead maze tied to the stage you just finished, and the goal is to pick up every egg in it for a free continue. It plays somewhat like Pengo, and it is hard.
Rex faces whichever way he last moved. Stand next to a green block, face it and press A, B or C, and it slides in a straight line until it hits something, then explodes. If it hit a dinosaur, an egg or another green block, that goes too. Use the blocks on the roaming dinosaurs, because one touch from them ends the bonus on the spot.
The blocks don't care what they hit. Blow up a single egg and the continue is lost, however many of the others you collect afterwards. You get one try at each bonus stage, so look down the whole line before every push.
How to beat the bosses
Most bosses absorb an enormous amount of damage, even on Easy, so each fight is a slow grind. Keep the roar (Up+A) for them. Its meter starts over every stage, so whatever Rex builds up on the way is best spent on that stage's boss. The game has no passwords or saves of its own, but playing online here you can press Save right before a boss and Load to retry from that spot. Each game gets one slot, so every Save replaces the last.
Why don't Rex's hits hurt Skriitch?
A comet circles Skriitch, and he loses energy only in the moments when it stops. Hold your fire until those pauses come, then hit him with everything Rex has.
Burning bones in Dino Graveyard 2
Red bones fall during this fight, and setting them on fire sends them flying into the boss. He loses energy only while at least his head is in view. Move until you can see as much of him as possible, then kick him in the head.
Inner Works 2 and Swamp City 2
Both bosses attack from openings. Inner Works 2 has two that shoot balls at Rex; burn them before anything else. Swamp City 2 has four, with bees flying out instead of balls, and the same plan works.
How do you beat the final boss?
Skriitch returns at the end of Jungle Jam 2 with more varied attacks, and the comet rule still holds. Without a maxed-out fire meter this fight is close to impossible. Grab every Fire Fossil in the stage and try to reach him without dying.