I like the game, it's a classic mobile auto scroller thingy. There's a lot of games out there on mobile which suggest this is a good design, each with their own spin: Subway Surfers, Temple Run, Piano tiles, 2 cars, etc.
Stay on the safe side: avoid spikes and walls, nice, fits the theme. It looks really good as well, but I'm really confused about the boss fight. The controls get a little wonky when you reach that point and it just makes things too confusing. I think it would be a better game without it, just turn mana into coins and make it go faster and faster, or use the mana to let you blow up some spikes/ become invincible for 3 sec, etc.
That being said, there's a lot of good in it, it's really polished, smooth and fun.
Congrats!