One of my fave hori shmups of that time.
Difficult, yes, but also very addictive. I own the PSX version and played the SAT variant long enough to be able to say that the PSX port has the subtitle "Perfect System" for a reason (the dev'ers also think so, btw.). The SAT version looks slightly better, though.
The music and sound effects create a very nice atmosphere, always loved Technosoft's style.
And yes, you can unlock some stuff, including Free Play, just keep on trying!
RBjakeSpecial is right about Free Range, it's THE weapon to master in TF-V, almost could be called overpowered (a fact the dev'ers adressed in TV-VI). Also make sure to use the speed adjust option to its fullest, choosing the right ship speed is essential in many situations.
Einhänder?
Hmm... never got into it to be honest but it sure looks good.