I clicked around the screen trying to 'advance the slide', clicked on the placeable blocks but didnt' see how to place them, and eventually went back to the previous screen. I don't know why I didn't try pressing the 'Press This Button' button... but on onscreen instruction to finish the level for the next tutorial probably would have encouraged me. If you really want to go all in, you could even hide the placement blocks for the first tutorial level, so that there's not the feeling that the player might need to engage with something they don't yet understand.
All that being said - I don't think I said this before, but once I figured out the game, I had fun and it was hard to put down.