The word "gimmick" by itself almost always has negative connotations, though - a cheap stunt or trick that's supposed to give a thing added artificial value. In a gameplay context, it's far more often than not a complaint than praise. QED. "Gimmick" has come to mean "new twist that I don't like". Sort of like with "hipster". What does this word even mean anymore? Hell if I know.
The reason I generally dislike gimmicks on a shmup isn't because they're "cheap stunts or tricks", I consider them to be simply a "special feature" of the game. The problem is that they often make things more complicated than they should be, forcing the player to use not only their reflexes but also their knowledge on how to exploit the gimmick properly in order to progress in the game. Shmups with gimmicks most of the time doesn't demand only raw skills to be cleared, but also a relatively high amount of strategy, which is something I'm usually bad at. It's not like I'm trying to say "pure shmups" don't require strategy, but the more significant the gimmick, the more strategy you will need.
In spite of that, shmups with only a few gimmicks are still acceptable to add a "catch" in the game. There's a shmup called Akashicverse, where you should perform input sequences similar to the ones from fighting games in order to activate special attacks called "Methods" to clear some stuff on the screen. By input sequences, I mean things like (↓↓) + SHOT or (←↓→ / →↓←) + SHOT. I didn't like it at first, but then it quickly grew on me. That's an example of "gimmick heavy" shmup" done right. As for 14.3, I'm still a bit distrustful if it will work properly or not. I won't deny it seems very innovative, but it will probably make the game feel more like a "puzzle shmup" than a "regular shmup".
Either way, I can still totally change my mind once I get to play it. Maybe I'm being a little too skeptical and things won't be as bad as I feel they're going to be.
