I've looked at a lot of R-Types and Gradiuses and what not, but I just can't find this exact thing.
2D side scrolling horizontal shmup, the level I remember was in space, some asteroids in the background (?);
As the level was scrollong there was like a big ship or space structure (man-made like) on the bottom of the screen you could go behind some parts of it, if you didn't want to fight enemies (?), so your ship would be behind the structure/ship.
The shield you could get was blue and looked like something out of Gradius-G. I don't remember the pick ups making the player too powerful, I barely knew how to play the game and kind a always failed at the end of the level, the boss or whatever had a lot of HP/I didn't know how to activate special attacks.
I played it on the PC (Windows XP), around 2004-2005, Europe. It must've been from a demo disk or something. That's what's bugging me, finding PC demos info is pretty hard for shmups from that period.
I've been searching for this exact game for a while now. I've found other games in the past that were also kind a obscure, but this one escapes the hell out of me.