When you collect all 10 coins why doesn't it seem like they don't give you an extra life sometimes? I got all the coins in the later levels of the game and I never got another extra life (like in the early levels) what I don't quite get it?

You only get 1-ups at certain point intervals. Normally getting the 10 coins gives you bonus points, early on it's probably enough to reach the level needed for a 1-up.

So you don't know exactly WHEN you get a bonus life for collecting all the coins? *It seems like they would give you an extra life in the later levels because all the ground is frozen and you only get (what i belive is) 15 seconds to get them all, but they don't seem to give you aqn extra life. One last thing, is the most lives at one time you can have is 4? Because once I get 4 lives then the bonus stage won't give me an extra life! please and thank you

Is it 20 coins or something like that for if you collect a certain amount of coins that you get an extra life? I have no clue...

I'm pretty sure it's at certain point intervals...I don't remember too well, outside of playing it once at a local arcade recently it's been years since I played it. I think the most lives you could have is maybe 6 or 7 unless you had a Game Genie (cheat device).