Rengoku 2: The Stairway To H.E.A.V.E.N. Cheats (PSP)

go to downloads on menu and find a router and download all armor parts.  there is leg part
that when overheated, it gives you a limited invicibility and letting you have a unlimited
ammo.  per wepon that you use each level of the game, the ammo count of the weapon will
increase also will the overheat increase.  best weapons to look out for are the gatling
cannons. and speedy leg parts. for the head, equip any type machine guns with many ammo. 
also download parts are also parts you win at the end of the game. if you already have the
download versions, and have used them through out the game the ones you get at the end of
the game are worth nothing compared to the download ones you used.  sounds confusing but
just compare the parts you'll understand.