well, in fact yes.

for the first few levels, there are not many things that can harm you. if a scared thing runs into you, you loose some health, as well as if you try to walk into something you were not allowed to. then ARMSTRONG will "guide" you out (takes half of your health though)...

but lateron, humans will fight back if you hit them, and in the last levels, there are only humans who fight back or even worse, cops and army personell who are jsut there to kill you. so its getting pretty heavy lateron.

lucky for you, you are not allone. some sick feallas, mostly wearing makeup and a long leather coat, stand around and well, they kinda like you. so tehy aid you with some energy, points or whatever you are in need (depenind on your health and score. if you have full health and enough score to win the stage, tehy give you somethign special. if you miss one of the two, they will give the missing, if you miss two, they will give you just energy).

also, not only are there many hidden objects to find, liek health, score or stuff, but also every now and then there is a hidden stage. find all of them to unlock a special ending