Contra 4 review at Gamepro.

"After a decade-plus of 3D missteps, Konami finally delivers a Contra title worthy of succeeding the SNES classic, The Alien Wars. One part homage and one part evolution, Contra 4 is two screens of delicious torture.

At first glance, Contra 4 seems like it would be a better fit for the Sony PSP. The wide screen could have accommodated the action better and the ability to choose between analog or digital controls would have been welcome. Konami, however, saw the potential that lay in the DS' dual screens and took the opportunity--to double the difficulty."

Full Source: Gamepro