Those of you looking for an alternative Halo fix don't necessarily have to resort to playing more multiplayer matches online. Developer V3NOM recently announced the release of the initial build of the homebrew game Halo Zero for the PlayStation Portable.
This release of the game is mostly a teaser of what it can do on the handheld platform. The content itself is still rather bare and is currently rather buggy.
Regrettably, the developer will be going on hiatus and will put the project on hold for now. V3NOM did mention that there may be a possibility of picking the project up in the future and reworking the code on a C-based platform (Halo Zero is currently written in Lua).
Until then, we'll all have to content ourselves with this pre-alpha release of the game. Before you take a look at it though, please make sure to browse through the Readme file included in the bundle before installing it into your handheld.
DOWNLOAD