My dumb ass, in the last update (0.4.4.6) made a few changes to the way the game gets the leader-board information from the server, so that it's updated in real time, or as close to it as possible.
This introduced frame drops when its trying to reach the server to see if there are any updates, as it waited for the server to reply before it continued. That was bad design on my side.
I fixed it now so there should be no more frame drops, hopefully.
I've also made a change so that if you're at max shields, and you loose a shield and are trying to pick up a new shield while the animation of the old one hasn't finished, now it will let you do so. Before you could not have a new shield until the animation of the old one had finished.