SMS shooters played: Power Striker, Global Defense, Bomber Raid, and Thunder Blade.
Re: Dragon Spirit and Cyber Core, both are really just building off Xevious, which pioneered that 2-level mechanic.
I own and enjoy Cyber Core, but I don't play it often because going through several levels uninterrupted isn't too much of a challenge. It's a nice, relaxing shooter, though, when I'm a bit tipsy at night.
If you like Dragon Spirit but find it too hard, the NES one is much easier in comparison.