Well, so far I like what I see. As for my thoughts, I think that having the game support a controller instead of just using the keyboard would be nice. The demo level had the right difficulty for a shoot em up's first stage, but I am guessing that the difficulty would increase in each level as you progress, and a shoot em up is more enjoyable with a controller rather than using the keyboard.
I am guessing the game has some lore, from what one can see during the stage, and that is a good thing because players like it when games have some lore behind it, we like to know why we are shooting the enemies. Even if its an ero game it should be fun, because while the ero might get some players to try it out, the fun is what will keep them playing.
The graphics are, of course, the strong point of the game. The characters look amazing, the backgrounds too. And the designs are well done. The sound could use some work since the voices were being too quiet when compared to the background music, but that is a sound volume issue, not a quality issue. The voice acting and the music itself were fine.