What is the complete story of the protagonist Sam?

The hero Sam has three versions: the first tells the future time and space, the second tells the past time and space, and the third tells the story of his return home.

Hero Sam 3, the first story, in 2032, mankind excavated an ancient civilized instrument, which was the most intelligent, and mankind lived a peaceful life from then on. However, peace is not forever. Aliens from Monochamus alternatus invaded the earth, wreaking havoc and destruction everywhere. So people decided to fight back. Sam Si Tong is the most experienced, courageous and physically perfect freedom fighter.

While searching for the alien opposite sex with his comrades, Sam unfortunately fell off the helicopter. After waking up, I began to contact other comrades-in-arms and a female soldier to prepare for the rally. However, in the end, only Sam was left, so Sam's code name in this game was "the last earthman". After going through various levels, I started to play boss. But in the end, although we defeated the four-legged monster, a huge meteorite has hit the earth. In order to save the earth, Sam jumped into the space-time machine and shouted, See you in three thousand years! Then, the earth turned to ashes.

Next up is the hero Sam. He made his first attack. Starting from the starting point, you will find that Sam stepped on a time machine, that is, he came to 3000 years ago. The earth is still safe and sound, but now Sam is the only one on the earth besides aliens. Sam once went through various levels and killed a four-handed monster in the spaceship.

Then Sam threw away all his weapons and ran to the bottom of the spaceship, only to be sucked up by a light ... and then the spaceship was blown down by the big-headed spaceship. Sam fell into a river, and the story of Sam's second attack began. After the last boss was killed, Sam called a man, his father, indicating that Sam is not the only one on the earth now. He succeeded. He saved the earth and everyone on it.

Then he entered the journey of Sam 2, and a doctor gave him an extraordinary ability to go to Sirius to destroy those aliens. So, Sam once again set foot on the road of hunting alien creatures. Or kill many monsters and finally destroy the base of alien creatures. Sam won the final victory. On the way home, I don't know what challenges he will face. ...