A friend of mine (no account here, hence I am posting) is looking for a shmup which he can not remember much of.
What he can remember is that it was an early 90s arcade game. Horizontal, R-Type-ish graphics, sci-fi theme. And the first level had weird horizontal-tube-like dragon enemies.
Not much to go on, but people here have figured out more obscure descriptions.
I doubt it is any of the Gradius games. He is not someone who is unfamiliar with games in general, so I am sure he checked obvious stuff like Gradius. Not sure about the Salamander series.
He seems to be afk again, but I doubt that those are it.
If he was playing at home instead of the arcade, it could have been the 2nd Part of R-Type I on the PCE/TG-16. The PCE was common in the early 90s in Germany and the HuCard version split the game, so he might be thinking of level 5 of R-Type 1.