(just happened to find this comment, actually this has been implemented! If you see the circles around the player increase in number as you gather more of the grey pick ups. It was so well nested in the sprite and the mechanics I almost missed it, had a "wow moment"!)
I thought the extra sprites for collection were a nice touch, maybe too subtle if people are missing it, but I noticed the change and it clicked. The understated design and teaching is nice, but hard in jams because I think we’re all playing a little quicker than we normally would because we want to try and give as much feedback as we can during whatever allotted time we have for a session, so you can miss a subtle hint that your abilities have shifted.