You can get it at the PS Store for under ten bucks. But be warned: the gameplay hasn't aged that well to say the least. But there's a twist: once you master the difficult controls and actually finish the game, it's extremely rewarding.
I wouldn't be surprised if the controls and wonky camera were by design.
I considered playing it sometime after MGS 4. Wow, that's a decade ago. Anyway, it did feel very dated even then, judging by some gameplay videos. I think I'll pass.
Totally understandable. I have a love hate relationship for it.