Besides for the accusations of plagiarlism for the main theme, presumably why it wasn't featured in MGS4 but I was watching the legendary action movie Speed the other day and the score from that is shockingly similar:

yeah it sounds similar

AND I, HAD, THE TIME OF MY LIIFEEEEE, NO I NEVER FELT THIS WAY BE FOR !! AND I SWEAAAR, IT'S THE TRUUUUUUTH AND I OWE IT ALL TO YOOOOOOOOOOUUU


Sorry about that,

Yes, it does sound samiliar.

MGS has a tendancy sometimes not to stray far enough away from its inspirations. Its fine if you're making a game that basically copies a bunch of shit from others, just change things enough to avoid lawsuits.