Algodoo

In 1974, the Arecibo telsescope sent a message to Messier 13 in the Hercules constellation which represents various componments of life
Now, in 20XX, an extraterrestrial species have sent a similar message to our planet. What does it mean? Is it an urgent one, or a warning?

I would stricly recommend try solving the puzzle before strolling through the comments for solutions. This is my first puzzle, meaning some stuff may not be as cryptic and original as other puzzles.
Inspired by UDG4's puzzle.