Nice, but...
Nice game but it does need a little bit of refining, for instance, I got a tower just under 544 meters just by scrolling up and clicking spastically. So yeah two main things:
1. If you can try and have it wait to measure height until blocks are relatively still.
2. Less importantly, it would kind of help if you restricted the placing of blocks over other blocks, like have the cursor turn red and stop them from placing it, like in some RTS games?
Overall though, sweet game, 5/5 9/10.