rising balloons or falling confetti?

In case anyone is looking for a super simple and low-tech way to do this, I just inserted some illustrated balloons (an illustrated bunch of 3 in different colors to make it faster) from the Content Library onto my slide. Then I duplicated it (CTRL+D) to make several of them. I made some smaller and larger and distributed them across the slide, then selected them all at once on the timeline and made them each last only 2 seconds before flying out of the slide (via exit animation). I then changed the speed of the animation on a few of them for more variety in the appearance/to make it look more realistic. This sounds like a lot but it only took a couple of minutes :) When the learner reaches a "congrats, you've finished" type slide, the balloons fly out.