I have completed Simon - the game. If you have a couple of minutes, please have a look and get back to me with the good (hopefully) and the bad. I used SVG to ensure that the circles remain circular when you resize the page.
Here it is: http://pauldebruyn.com/html/simon.html
I played a couple of rounds on your Simon game. I like the responsive design for sure. An issue I found is, let’s say I am on the 15th round of a game and the new sequence has just played. If I press the wrong button right at the start, it should go ahead and alert me of the error and replay the sequence (in non-strict mode). Instead, I have to press any button 14 more times, before I can see the sequence played again.
Thanks for the input. I remember reading (Wikipedia?) somewhere that this is the way the original game worked. Annoying? Yes, for sure. When I have time I will go and put logic in to check the tiles as they are entered, and respond if an error is encountered. Again, thanks for taking a look.