For me, after the third level friggin Shinobi is impossible. I love the style and gameplay of the game, but damn it. I'd get 3/4 through the level, blink, and fall down a chasm and restart the whole fookin thing. Also, the orginal Metroid b/c I could never find my way around b/c of a lack of a map. Then again, i was about 6 or 7 when I played it.