Thanks for your quick answer.
Well, today I redownloaded it again from MEGA and Pixeldrain.
Finally from Pixeldrain I have managed to extract it without problems although from MEGA I still get the same error.
Bash:
md5sum -c <<< '638c1a38664eaedd8068cde4efa67466 StarPeriphery-Release4.5-linux-MEGA.tar.bz2'
StarPeriphery-Release4.5-linux-MEGA.tar.bz2: OK
tar -xvf StarPeriphery-Release4.5-linux-MEGA.tar.bz2
StarPeriphery-Release4.5-linux/
StarPeriphery-Release4.5-linux/StarPeriphery.py
StarPeriphery-Release4.5-linux/StarPeriphery.sh
StarPeriphery-Release4.5-linux/game/
StarPeriphery-Release4.5-linux/game/DejaVuSans-Oblique.ttf
StarPeriphery-Release4.5-linux/game/Roboto-Light.ttf
StarPeriphery-Release4.5-linux/game/Roboto-Regular.ttf
StarPeriphery-Release4.5-linux/game/archive.rpa
bzip2: Data integrity error when decompressing.
Input file = (stdin), output file = (stdout)
It is possible that the compressed file(s) have become corrupted.
You can use the -tvv option to test integrity of such files.
You can use the `bzip2recover' program to attempt to recover
data from undamaged sections of corrupted files.
tar: Unexpected EOF in archive
tar: Unexpected EOF in archive
tar: Error is not recoverable: exiting now
I have downloaded the file from MEGA once again but it still fails, even though the md5sum is correct (weird).
Maybe the file was corrupted on upload?