It's good.
I'm not a shmup expert and generally find complicated score mechanics to be off-putting. I almost never play for a high score. But I think the score mechanics were presented pretty well in this case and aren't too crazy, in that they reward aggressive play and aren't too fiddly (compared with something like Ikaruga, for example). Once I realized the secondary weapon's similarity to Mars Matrix, the mechanics started to make more sense.
I really like the tutorials. I don't think I've ever seen shmup techniques explained like that in-game before. I think that helped make the game more accessible, because otherwise it "feels" like an expert shmup for expert shmup players.
The one piece of feedback I had was that I wasn't able to tell the difference between the purple medals and the silver/gold medals in the heat of battle and just collected all of them. More distinct shapes / colors might be nice. Also is there actually a point in the silver and gold medals being different? They seem to do the same thing score wise.
I'm looking forward to the full release.