Great shmup. Really good pixel art and soundtrack. There are some cutscenes in-between stages which are pretty nice.
You have 4 weapons and you can switch to any of them at any time by pressing one of the L1,L2, R1 or R2 buttons.
Multiple difficulty options. I found this to be pretty difficult on anything other than easy. I think I'm just bad at this type of games.
There is also a score attack mode which is a separate stage. I spent half of my time here trying to at least survive until the end.
I Highly recommend it if you want a charming and fun shmup.