Very fun game, could easily become a full game with a bit more polish! First of all (as said already) it would be nice to have outlines for the blocks to know when multiple are stacked on top of eachother (although this way there is more instant regret...) and it would be nice to have some more mecanics, maybe add a fan that slowly blows blocks away? Leave holes in the tower from the start or add explosive blocks? Or create a tower with a corner in it :) would love to play it again!
Again the main mecanic works very well, it is tense to see the blocks balancing after deleting one, and very fun to climb up your own franken-tower to the finish line!