Played the web version.
I like the idea that your ghosts of your previous runs help you in the current run but I miss a challenge in the game. Currently I feel you can spam any ability until you have enough ghosts to kill the boss. There's is no reward for doing a good performance it seems.
Also at my first run it felt a bit confusing because I picked a character with only buffs so I couldn't attack.
I like the music, although a bit repetitive after a while.