Here is a gameplay of your demo:
I really like the idea of a flying Templar knight with guns, reminds me the one from Shin Megami Tensei. I play your game with a Xbox controller and it feels fine for me, I had no issues playing the game. On the other hand, the strafe is nice to have it but I din't find many situations in which a I really need it, mostly because I can skip the bullet hell sections by just destroying the enemies/cannons with my own guns or using the shield bomb.
The Boss... I like it as first tutorial boss, but in my opinion future Bosses should spawn bullet patters in a touhou fashion, that will make the game feel more like a bullet hell (I also liked the music: BOSHI BOSHI BOM BOM BOM!!!).
The last level with the aliens: the flying ones are too fast and difficult to avoid, and the homing projectiles of the ones on the ground are very sticky/hard to avoid. To the point that is more easy to ignore them a just go forward while using the shield bomb. But Still I like the space design and avoiding the meteors is fun.
Overall, I like your game, keep the good work.