I've just spent far too long writing the beginnings of a ridiculous music game for web browsers. You use either a MIDI keyboard or the computer keyboard (a s d f g h j k). The game plays a bar of random notes and you have to play it back, correct notes and correct timing. As you level up, the patterns get more rhythmically complicated. If you make 5 mistakes, game over; you have to start again. Still probably a lot more to do to make this more interesting, but I'm curious as to whether anyone finds this remotely worthwhile.
One challenge right now is how to calibrate if you don't have absolute pitch. I feel like I might need to add some sort of screen where it plays you a few notes until you find the right ones or something. For now, note that it's in A minor, A3 to A4.
https://files.jantrid.net/simus/
Simus

@jcsteh I love this even though I keep failing at it miserably.
@KaraLG84 @jcsteh It's funny how terrible at this I am. I don't see this improving. I suppose it's just like typing Yes. I'm one of those people without perfect pitch.
@ppatel @KaraLG84 @jcsteh lol I keep thinking A maps to C so i keep overshooting, but this is one Simon variant I actually enjoy for longer than five seconds. A scoring system would be awesome :)
@zersiax @KaraLG84 @jcsteh I can't wait to be at the bottom of the leaderboard.
@ppatel @zersiax @jcsteh Race you to the bottom. lol
@KaraLG84 @ppatel @jcsteh lol I got a score of 32, good enough for now :P
@zersiax @KaraLG84 @jcsteh Showoff! My last score was 22 or something in the low 20s.
@ppatel Perfect pitch shouldn't be necessary once you find the relative position - good relative pitch should be sufficient. But I definitely need to find some way to help calibrate your ear at the start. @KaraLG84
@jcsteh Yes. Exactly. That's how I've learned to tune my guitars and how I used to learn piano music. @KaraLG84
@ppatel Note that you can play the keyboard for the 2 bars before the melodies start, which should help you calibrate. But ideally, I'd like something more guided. @KaraLG84
@ppatel @jcsteh @KaraLG84 This is a wildly different concept to what you're doing but it popped into my head just now. With some modifications, what you have here could be a fantastic tool to learn pieces of music on the keyboard by ear. Take a thing of sheet music, split it into bars, allow user to pick one or two hands, keep playing the bar until the user plays it correctly, then move on. I don't think anything like this exists currently