Game completes itself..?

While playing the first two acts of green grove, I collected all the emblems in act 1 as well as an emerald. I then played through the time trial for said level. Going into Green Grove Act 2, I had 6% on the game. After beating the act and collecting what I think was all the emblems, the game inexplicably gave me a screen saying something like "Congratulations: You one hundred percented the game! You can do score mode". Not exactly that, but that's what I remember. I then returned to the map screen to see that I had apparently collected every single emblem in the game, as well as every emerald and (I think) every time trial, with 90% completion status.