These are "Pixel Bricks". They're basically sort of a clone of those 1x1 Lego bricks, but packaged as their own thing. The bricks come loose in a bag inside this box. Using the instruction sheet inside (announced on box) you can build these sort of abstract...ish...like figures for Sonic & Tails.

The box says about how you can build your own figure / toy. The red splash has "Instructions!" and "Actual size!" It also says there are over 170 pieces inside to assemble. Are these a UK exclusive item? Are they sold in toy or game stores too?