The Red Algae (হার্ডকভার)

A little boy named Shishin started his journey towards earth from the planet Ulin. A dangerous space accident separated him along with his pet Toma and third-level robot Bitu from their spaceship. At last all of them landed on a strange planet with their scoutship. The whole planet was covered with water, with long rows of red and green algae everywhere. Right after they landed, they understood that many human beings had died on this planet before. The moment they were struggling with getting food, shelter and medical treatment, they encountered the dangerous red algae. Some dangerous creatures that lived under water joined the algae in creating trouble for them. Did they survive till the end?