Zero Hour is a cancelled third person shooter / action game that was in development by Argonaut Games for the PSP. The project started out as a Playstation 2 game, but when Argonaut got PSP early development-kits, they decided to port Zero Hour to the portable console. A demo for the PSP version was shown at E3 2004, but in late October of the same year, Argonaut fired 100 employees and was put up for sale. Lack of a constant stream of deals with publishers led to cashflow issues and a profit warning earlier in the year. Zero Hour vanished with the closure of the studio.
Thanks to USERDANTE and Tanguy for the contributions!