Blocks that look like 1x1 can be 1x1.2 for example. Not knowing leaves much of this game up to luck, which makes for a pretty weak physics game. Also, there's sometimes an issue when stacking blocks to the right or left of center: When you try to place a block, it re-centers the drop point so that when you think you're dropping a block to the side, you may actually be putting it in the middle of your tower, causing it to fall.
If the kinks were worked out, it would easily get 4/5 stars or better. But for now I give it 2...
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