Nice, but unfair
Its a nice idea, but the waves ar to hard later. After the second boss it spawned 4 of this zapper-things, which paralyse the "hammer". That was the time, when I lost a lot of money and then died at the 3. boss.
Is there a way to kill this things?
When I think about this... I dont want to play it anymore, because I dont think, that I will get far behind the third boss. Except he was the last boss.
Some upgrades would be cool. For example a faster swing of the hammer or faster movement, more power to crush the metal-guys with one hit and so on. Maybe also a higher and better recovery rate after someone got zapped.
The player could decide to spend the money, which makes the game easier, but gives you a lower score... or leave it as "hp"/score.
That would be also more strategical for your game, because everyone has to think about what adjustment would be the best to survive long.
@chazzybigdog: The bosses arent that complicated or invulnerable.
After you cut the rope, the two things on the side of the boss disappear for some time.
Thats your time to move you ass up to the head and smash it.