Contra 4 review at Siliconera.

"Talk about taking me back to the old days. Quite simply Contra 4 does everything to pay homage to the old 2-D sidescrollers while avoiding the pitfalls of copying them exactly. I mean let's be honest, those games WERE great, but they definitely had problems that we really wouldn't (or shouldn't) tolerate with new games these days. So yea, go out and buy Contra 4 post-haste (that means like now). Why, you ask? Let me count the ways…."

Full Source: Siliconera