The initial flip where you see everything allows me to get about 5 kaiju without doing any of the primary game mechanics.
The numbers are not a good feedback system. I would much rather see a symbol on the tile that means how many steps away the kaiju is. or something like a different alarm sound if one is close.
After you click a different tile, you can no longer check the previously clicked tiles. This makes it really hard to calculate things.
All that said, it was a really good concept. I like the hexes, and it fits thematically with finding a kaiju in a city via it's footprints. (ooh that makes me think that you could have some tiles that would lead to the kaiju have some footprints as though it just passed by here.)
The ambient sounds are good, but I would prefer some nice cerebral music.
Good job.