A lot of our graphic designer's work unfortunately didn't make it into the current version including the big WARNING screen on boss approach, and indicators when enemies were approaching from behind or the sides. The level 2 song was written but not recorded in time so it plays level 1's song again. The intro was going to transition from the backstory with the slow theme into a more intense cutscene that plays with the main theme, but the art wasn't finished for that so the main theme just plays near the end of the backstory. There was going to be a powerup called BRACE Mode: The ship's wings would be bound up, the player would become invulnerable and grazes would delete bullets, allowing you to build up the Impact Drive risk-free while also clearing the screen. The ship was planned to have a voice done via vocaloid, and just say things like "checkpoint, impact ready, warning" during the course of a mission. And finally, there was more lore, but I like keeping the dialogue short and sweet.
There were some things that I already knew weren't going to make it in when we started, and that's scoring and a TLB. Scoring is kind of a big part of shmups for serious players, but I've never been that good so I've never studied what makes a good scoring system. I am planning to add a true last boss to game that will reveal additional lore, but as usual it will require playing start to finish without using a continue.