Help with iPSC

Hello everyone!

I am culturing iPSC and I am quite new at this. The cells are behaving a bit weird and the people in my lab that are experienced with them are on holidays right now and I don't know who to ask. There is this weird dark thing on top of the clusters of the cells. It like clusters of quite dark and not so dark dirt/cells/debris, i am not sure. And the cells are not growing along the surface, they are growing kind of vertical? The colonies are really visible without microscope on the flask... What does this mean? Are they differentiated? or contaminated?

Thank you all for your time.