I started playing this game and got hooked immediately. The gameplay is very similar to that of Touhou games (I was a huge fan of Imperishable nights) myself. I didnt know of any real good cave or Touhou ports to android, and Im pretty happy with this one. Im also a fan of the Cave games and this game was quite similar but slightly different (not as many enemies, slower and more complicated bullet patterns, harder to destroy enemies). The slow-mode in this game is a little interesting. You can use slow mode as long as you want but it affects your score (not sure but you get a bonus if you dont use it or something like that).

Pros:
-Lots of levels
-Quite impressive bullet patterns
-Controls are excellent
-Great frames per second (Im on Galaxy S2 which is quite outdated now)

Cons:
-Music is repetitive
-Only 1 character (well its a story about her so I guess that cant be helped).
-Full version isnt free. Its $1.99 now (Log in to see links)

I ended up buying the game because its nothing compared to the $60 I spent for Dodonpachi. Definitely worth $2 but it doesnt have as much content as my favorite Touhou games (PCB or Imperishable nights), but what can you expect from an Android game?

Overall I recommend downloading the free game for sure and see how you like it for yourself.