You're looking for a way to download God of War: Ascension on PSP or Android. Here's what I found:
God of War: Ascension was released on the PlayStation 3 (PS3) in 2013, but there was also a PSP (PlayStation Portable) version of the game, simply titled "God of War: Origins Collection" or "God of War: Chains of Olympus" and "God of War: Ghost of Sparta" which are part of the series. However, I couldn't find any information on a PSP game titled "God of War: Ascension".