Thank you for playing the game and for giving your thoughts, its always great to hear the opinions of someone who's not a fan of the game's genre.
I'm glad the difficulty curve worked as intended. First introduce a concept/mechanic, iterate on it in gradually harder trials then provide a final 'test'. That was the core design philosophy for each 5 levels of the game, with the last 5 levels bringing everything together for a final set of challenges.
I'll put some thoughts towards a mobile version.