I enjoyed playing it. The animations were so simple, but the count of the animation frames is just awesome. You made a really good job of animating all of those movements for that short period of time. Good job!
I didn't like one little thing still. At the start, you teach how to deliver mails, and it feels like I ended up 1 level and it should be a level system in the game. But the next level is unlimited. I didn't realise it at first, and I tried to figure out what I am doing wrong that I can't finish the level.
Maybe you can do the "teaching" phase in 1 single level then, so the player will just continue playing it. Or maybe, even better, if you can separate the game into different levels, so there will be a progression system.
Anyway, I really enjoyed it. Thank you!