No offence but I have a idea.have a game made called'starwish:plot gaps'.basicllydepending on the player's save file on starwish,they can see extra cutsences(and maybe extra missions)e.g.how did the wishing star spilt into 7 pieces?
note:if you do make a squel,here are some ideas for super major bosses like the earthwall:lightghost(fastest feduration ship)littleskull(smallest feduration ship and still really strong and powerful even though it's small)bigdipper(biggest feduration ship).just some ideas if you make a sqauel.