fun, but too easy.
at first it was fun while trying to upgrade.
but now i have 10 buzzsaws, level 20 flow for each valve, and countless mines, turrets, and sentinels.
i pretty much just minimized the game, worked on flash for 30 minutes, checked facebook, and when i came back i had and over 2,000,000 combo. as i write this it is still going and i check it again and it is a 2,191-thousand-something combo.
im going to go to a game and leave this open and check my combo when i come back.
in short, it is just really, really, really easy once you get enough upgrades.