crazy... didnt know how to do background though...

Can yall play Newgrounds games on a Mac? I try all the time. It seems like hit or miss.
And since games are just about the only reason I go on Newgrounds, I would like to figure out how to play certain game. I do have a regular computer and it works fine on it. all of em.
I can see the game and click on the game, etc. with my mouse. The problem comes when I try to start playin and using the cursor keys, etc. The game still plays but I can't move around or do anything.
My only question is: Is anybody else havin this problem?
Thank You

this is my first post.
And im glad im using it to wish yall a happy easter.

:)