[UPDATE: Sorry for the confusion, guys - we were waiting to get more info. This seems to be a Cave Story hack or mod - we're not sure if it's with Pixel's approval or not. Translation help is welcome.]

Hack9 is a Cave Story mod which requires some knowledge of the Japanese language to play, featuring a storyline unrelated to any of Pixel's creations. This version is labeled 1.0, and presumed to have taken the developer over a year to develop.

Use the cursor keys to move, and press the Z key to jump. Tap the X key to shoot when you've acquired a weapon. The status and inventory screen can be accessed using the A key. Choose the first option from the main menu to start a new adventure, or select the second line of text to restore a previously saved game. (additional video and screenshots in the extended, Vector link)

Name: Hack9
Developer: Kazuhiko
Category: Platformer
Type: Freeware
Size: 20MB