Garnett, I'm not usually one to tell people their opinion on this or that is quote/unquote "wrong," but I was hyped as hell for Sine Mora based on all the praise it received leading up to and after it's release.
All I can really say is that your opinion is incorrect. Sine Mora is not a good game.
- The planes are squirrely and twitchy at the best of times, nevermind that they move at the same speed even when the much lauded slowdown power is active. What the hell is the point of a slowdown mechanic where you still move at the same speed? All that does is give you more time to look at the bullet patterns as your twitchy little gnat of a plane bangs into them.
- Boss hitboxes are small and fussy. Hey, I'm all for moderate bullet spray, but the rule of thumb in good shmups is that you're shooting in the general direction of the enemy while your primary focus is on weaving through bullets, protecting your own hitbox. Having small targets all the while means you're only dealing damage when lined up with a specific horizontal slice of the screen. In a game where the time limit is your health bar, this presents a problem.
- Tons, and I do mean TONS of "aha, I gotcha" moments, where enemies or obstacles fly onto the screen completely and utterly without warning or without adequate time to react. The bosses in particular are really bad for this, often having sudden, fast moving attacks that sweep the entire screen. Cheap hits is not the same thing as challenge.
- Some bullets or obstacles blend into the background. Ever notice how Cave and Touhou shmups tend to have large pink and purple bullets? There's a reason for that: you can fucking see them! It's the same reason why the backgrounds tend to have a muted colour pallet.
- Two words: Gradius Syndrome. Your success in several areas is more or less dependent on how powered up your guns are. If you lose your powerups, good bloody luck.
- Powerup drops are anything but balanced.
- Poor level design and pacing.
- I will concede that the art style, music and story are all amazing, but that's not really what you want to hang your hat on when making a horizontal scrolling shooter.
- On the whole, I wouldn't call it garbage, just very amateurish. There's still some fun to be had, but the design just seems kind of haphazard and poorly thought out.
If anyone out there is curious about the genre but found the whole danmaku thing to be too intimidating, I urge you, don't pick Sine Mora as your gateway game. Jamestown is cheaper and a better game in every way.