Really fun! Is this a totally original mechanic? Obviously it's a play on tower defence but I don't recall playing something quite like this before. Level 4 stumped me, but I skipped and played to the end of the game, really enjoyed it.
It would be interesting to develop the idea and add more mechanics - bouncy roads that let you jump over towers, towers with different ranges and abilities... How about a tower that shoots bouncy bullets that knock you to different squares on the map? Maybe there could be ways for the ghosts to destroy the towers? So much potential!
I would also love an undo button or something like that to stop having to reset!