EP1 Message: Yay 3D! EP2 Message: Yes! 29 is figured out! EP3 Message: Is this comedy? EP4 Message: Yay... Three Times Table! EP5 Message: 31 and 32 are figured-out!
C2A. And here's the proof: https://www.radiotimes.com/tv-programme/h2xffr/numberblocks-season-5/#archive Press space for next backdrop.