Excellent and Refreshing Idea.
I´ll start with the good points :
It was very fun to dodge zillions of pellets/lasers/bombs while shooting 2 machineguns, and the music fitted the action just fine, I don´t think the game got too repetitive. The difficulty curve was there, each lvl becomes a little harder than the previous one, just how it should be. With only 3 types of enemies, it´s the mix you do between them wich creates different type of "stress" to the player, so I actually think each lvl is very different from the previous one.
Now the bad :
1st of all, RANDOMNESS, My main complaint is the randomness of the game.
As you can´t really aim with the ragdoll, after lvl 3 the game becomes more of a "dodge to survive" and less of a "shooter", therefore, you can´t really predict when an enemy is going to die, and even if you can, there is a chance that the path you need to do to get the precious heart is covered with bullets... this sucks big time.
2nd The bomber :
I guess you tought that making it drop its bombs at different speeds would be cool, but in practice, it´s only annoying... because the "patterns" the bombs do, often get you cornered with the lasers/pellets, and there are sometimes when there is really nothing you can do... except die. Randomness here again.
3rd The movespeed/acceleration of the ragdoll.
I loved the system, don´t get me wrong, (i´m not even going to mention the fact that my keyboard kept beeping each time i pressed 3 keys at the same time, and that just happens in this game, I play cs all the time and never got this problem),
the problems begin when you have to face 3 different types of enemies, the ragdoll simply does not respond in time to some of the sittuations the game generates, wich is unfair and frustrating.
I know it´s only an opinion, but to make this game better (humble, respectful advice) :
Powerups Spawning : Maybe some invulnerabilty for 5seconds, doubledamage, additional speed ... you know...
Either fix the Bombers patterns or increase the ragdoll speed (just a bit).
Make the hearts fall with a parachute or something (give additional time to get them).
Good luck on making a good game, a better game , and GOOD WORK.
Wooh, that was a long review ^^.