Battle On Guan Bridge is a fun, solid prototype for a shmup.
The central premise is that you can move both your character and your path through the stage. I'm not 100% these are different things in the current build (you can just move the bridge when you move your character, and then it's sort of the same as a regular shmup,) but if the bridge could take damage? Or if you could dispose of rolling projectiles by moving the bridge out from underneath them? There's a lot of potential here.
Overall, I'm really interested to see where this goes!