Notes for this version: Callisto is using pretty much all the memory that the PSP has to offer,
and there are some memory limitations with the current loaders
according to the developers.
Notes for this version: This newest version has had changes. Callisto v0.2 shows a new planet
to raid, and with that comes new enemies and weapons to fight them
with. There will also be new power-ups and new bullet and enemy
patterns.