Well thats exactly why I asked brunopalermo . Because the fact is that eighter option can work just as well with the type of game I am making. So at that point the only thing that matters, in my opinion, is what most people would enjoy more.
I know it's impossible to please everyone, so I made it a point not to obsess over that when I decided to start doing this. That being said if a person is gonna try a level a bunch of times, fail repeatedly, then has to quit the entire game because the levels are locked; if that person represents lets say 1 out of every 100 people out there, then cool, I'll lock the levels and not worry about it; however if that person represents 1 out of every 3 people out there then I'd rather leave the levels open.
That's why I am trying to get a sample of the public here.
So come on everyone, don't be shy, would like a bunch more opinions please.
P.S. A star system is an interesting idea, I'll look into that. Thanks Burvey , Aphrodite , Somebody