Mystery at 4,000 Fathoms

A glittering submarine, a missing brother, and some encoded charts. Will you survive the discovery of a lifetime?

1
A glittering submarine, a missing brother, and some encoded charts. Could Atlantis be real?
2
You must aid the Bellerophon using its large mech limbs! But what's out there in the gloom?
3
You're plunged into work in the city. Can you keep up, especially when a threat comes out of the blue?
4
You're on the trail of a stolen submarine! Can you stay safe on the sea floor?
5
A saboteur on the verge of victory. Only you can defend Atlantis.