Great game! Congratulation on using all the wildcards, that's impressive!
Maybe, an idea would be to give more ways to remember the sequence, such as in level 4. For many levels, my best way to have a good score is to learn the sequence by heart, which is less fun than when you still have to improvise a bit ;)
Also, congratulations on the audio, menu, transition and smoothness of the game, making it feel very good!