Cave

In a small coastal town in the West of Ireland, a rebellious teenager named Shain convinces four of his friends to explore the cave on the cliff face.
For centuries it was forbidden to enter the cave.

Young and naive, the 4 teens decided to explore the mysterious cave on a whim. It would be a great place to hang out. Since there was nothing else to do in the rural town.

At least they prepared some supplies for the venture. Like flashlights, snacks, water and chalk to mark the wall. They marked the cave walls to remember which path they took.

They sludged through the damp and dark cave.
As they travelled deeper down the narrow cave, they noticed debris gathering on the cave floor.

Suddenly, they felt a breeze blow past them and the cave became much wider. The tight narrow path disappeared and the air suddenly felt colder. The teens were on the edge of a large opening. It was impossible to measure its size. Their cheap torches failed to pierce the pitch black darkness.

The five nervous teens began to enter the clearing when Shain knocked against something hard that wasn’t the wall. He shone his torch down to his left to see what was blocking his path.

He never expected to find an old Bouncy Ball coin machine in the ancient cave.
In the dirt beside the machine was an unusual silver coin with unfamiliar characters engravings. Curious, Shain picked up the coin and put it into the machine.

Shain looked at his friends for permission. Using all his strength, Shain turned the stiff silver knob and watched a colourful ball spiral down to a stop at the metal flap. He opened the flap and picked up the ball.

After picking up the ball, a series of loud bangs echoed through the dark cave (Sounds like a ferris wheel being turned on).
The last bang, lit up the cave like the opening of a dramatic stage performance. Blinding white lights shone forcing the teens to shield their eyes from the overwhelming light.

When their eyes adjusted, they peeked back into the clearing shielding their eyes from the full power of the overwhelming shine. It only took a few seconds for them to notice something huge in the centre of the clearing. The five teenagers gazed in awe at the giant fossilised remains standing under the spotlight.

Overwhelmed by the unexpected discovery, Shain dropped the ball which bounced through the clearing, eventually hitting off the strange structure.
Like an egg hatching, the stone surrounding the reptilian fossil began to crack after being hit by the small ball. The stone shell crumbled away to reveal something even more alien (unbelievable).

A black-scaled metallic creature emerged from the rock. The dark figure shone under the contrast of the white spotlights. Its shape and size resembled the ancient creature spoken of in the villages old wise tales…. The Cave Monster.

Red lights travelled through the grooves of the structure like headlights of a car powering up.

What had started out as a dare-devil expedition, quickly turned into a situation beyond the teens wildest imaginations.

Deep in outer space, a militant planet picks up a signal on planet Earth. The commander recognises the signal sequence. “The Last Relic has finally awakened”.
Now they set course for Earth.

NOTE:
The creature seemed to power up when the bouncy ball touched it. I think the bouncy ball are keys (kind of like Power Rangers morphers)