English Title: Metal Slug 4
Japanese Title: メタルスラッグ4
Publisher: SNK Playmore
Developer: Mega Enterprise
Genre: Action
Released: Sep. 22, 2004
Product Codes: SLPS-25376 / JAN 4964808300501
For some reason, seeing straight standalone ports of Neo Geo games on the PS2 strikes me as almost a waste -- no disrespect to the Neo, but the PS2 is leaps and bounds beyond in everything but RAM capacity. It doubly so feels a waste when it's a port of the weakest entry in one of the Neo's most venerated series.

Metal Slug 4 was produced in the interim between SNK's bankruptcy and Playmore getting all the rights back, and was developed by an inexperienced team in Korea who simply took bits of the previous games and slapped them together however they could make it fit. It's a good enough port, I guess, but if you're going to play Metal Slug then you might as well play the good ones (1, X, and 3 of course), which are available collected together with the lesser entries on the PS2 anyway.