Oh, absolutely~! From just about any of the Windows games, the backgrounds and designs are stunningly gorgeous; I don't think I can find it in me to say a single negative statement about them (in fact, half of the time while I'm playing, I'm wondering what methods and tools he used to create them)~
Oh yes, the backgrounds! They're absolutely gorgeous, I wonder the exact same thing! :3 It's really nice to see awesome 3d and moving backgrounds when you play a STG. Eientei was my favorite, with the eternal dark corridor and the rainbow/purple/cosmos path. Amazing. Plus, it becomes even more obvious when you check what was the background behind the bosses:
Remilia: Scarlet red moon in a dark night
Yuyuko: Cherry blossoms tree
Kaguya: Full moon shining with purple waves of moonlight
Shikeiki: Beautiful flower field
Kanako: Suwa lake
Utsuho: Nuclear reactor's core
Byakuren: Makai's twilight
Miko: Admittedly a bit less impressive, but still a nice night sky full of divine spirits.
I dare you to find games that top those listed here.