You got 308? What a blessed run. I tried endless I ended up getting a worse score XD.
I would say this is polished for a first game, all the main menu buttons work, the sprites look good, thanks for putting A/D keys on the controls, and there's even the dragon lore there haha.
The only problem I encountered was the bgm didn't loop for me, and the armor pickup needs a buff, I felt the other powerups to be more beneficial. Anyways, I am looking forward to see what you create in the future :)