MBG's Shoot1UP enables the player to control
a whole fleet of ships by collecting 1UPs which I found really innovative for a shmup, and wiping the enemies off the screen with the united shooting power of the phalanx is an absolute blast.
Those are major gameplay changes and additions, but there's also a
whole list
of new NPC mining
fleets,
ships, balancing, a new character sheet, and the Roqual Industrial Capital
Ship also features some changes.