There is something that they have in common, that only these five games have. ONLY THESE FIVE. (It's hard, I don't expect most people to get it.)
I'm taking a guess here, but they all have plots that involve the main character either not knowing the specifics of their goal, or either being alone? Unfortunately, that's probably not true; if it was, you would probably have made a Journey one.
Give the cat the prize! Your prize is... A Request! (Not that it matters since I'll give you one just for asking.)
BEHOLD! Darthkitten's loyal solders, the F.E.L. Troopers! Because they are cats, they have excelent reflexes and hunting abilities, and can acctualy AIM, making them over 36 times more dangerous than your normal stormtrooper.
I watched about 10 minutes. Seems like nice guy. Such a shame about what happened to him on KOTW though. That's how I found him, TB tried to help him.