You can’t use original images or trademark names, but you can clone the gameplay; there’s no copyright against that. The Tetris trademark covers any Tetris style game ending in “tris” and titles that look like Tetris, such as “Tetr1s” or “Tetriz”. Other than that I’m not sure if any other titles have such restrictive trademarks - but then again Tetris is one of the biggest selling games of all time, being bundled with the Game Boy and all.
I would suggest starting to code games while keeping day job for 1-2 years. I’m in the same boat in my 30s as well but with a kid coming… I give myself about a year to go gold with several indie games and keep on going living off the “long tail”.
Actually I tried that to no avail. At least in my current job there just isn’t enough spare time. But maybe just witching to freelancer state might do the trick in this respect.
Actually, it’s 9.5%. I’m planning to use BMTMicro.
But my point was that there’s a minimum fee. For BMTMicro, it’s only $1.25. Even if you sell a game for less than $13.15, you still have to pay BMTMicro $1.25. If you charge $2 for one level, you’re only making $0.75. There’s little point in selling anything with a payment processing service for less than $19.95.
I’ve considered doing much the same thing because my job pays barely enough to live on anyways.
But I tell myself that if I can save up some money now, the interest on it will increase the amount of freelance time I’ll be able to have later.
I’m only 27, and I figure it would take me until 55 to “retire” from my job and make video games for free. I’m working on stuff in my spare time, but, like everyone else, I just don’t have enough spare time. In any case, I will eventually do the job I actually want (programming video games) even if it takes me most of my life to reach this goal.
If I suddenly start making money from game programming, my life will be alot better. A series of errors has put me into my current situation, but I think I can make my way out of it if I don’t do anything rash, like quitting my job and going freelance.
Nobody gets out their credit card for a $2 purchase. I wouldnt either. You sell stuff for $10 or more, and then it all works out peachy. Besides, you’d make the square root of bugger all profit if you tried to sell for $2.
Cas 
Well, I’m clearly on the side of “do it for fun”. I currently have an unlimited source of such
entertainment at Boardspace. Of course, my idea of fun may not be the same as yours.
If your definition includes wealth and groupies, I’m afraid there’s no hope.
My other “greater fool” alternative is a real possibility, but be warned that the commercial
games industry is a soul killing meat grinder from what I’ve heard.