Version 1.2:
- Fixed issues in levels 1, 3 and 6, to avoid getting stuck in certain places
or being able to get to places where you should not be able to.
- Fixed bug that caused the game to crash when a double-sized enemy fell
below the current screen.

Version 1.1:

- Fixed compatibility issue with Sony HB F500P and Sony HB G900P (maybe
others). Thanks a lot to Armando Pérez!
- Fixed writes to PSG register #7, that were breaking joystick support in some
models.
- Fixed potential cheat that allowed players to start level 1 with a high
level and better weapons after playing a later level.