This was a fun concept with a great sound track. I was not sure what to do at first because the question mark icon did not stand out to me immediately. If it shook or flashed a tiny bit at the beginning of the game it, might stand out more. Ideally, an optional tutorial showing you how to place blocks would be nice.
Once I understood the rules, I liked deciding where to place the blocks and watching the smooth movement of the red dot seeking out the yellow ones. I was confused at the end of both times I played when around round 3 or 4, I placed one block, clicked the button to discard so I could delete the second one (I had exactly 6 points, so I could), then for some reason, all the blocks exploded and it said game over. I had not even started the round yet.