Unoriginal, though well executed.
'Simon' is one of the oldest computer games in existence and this plays almost identically - though a few extra tiles and the fact that the length is only increased after 3 rounds is notable.
The first time I played, I didn't realise that each length needed 3 victories to proceed and it seemed a bit irritating until I got to the length of 5 and upwards.
Maybe you could have asked for only one victory at length 3, 2 at length 4 and 3 thereafter? And to ensure folk understand the rules, don't progress us after a mistake - instead we should play the same level again.
I loved the way you quickly repeated the pattern after a fail and the music and graphics were lovely.