Old School Nintendo Games

I have a Nintendo Wii, and with it I have several new fancy games that would be inconceivable back in 1986 or so. I have enjoyed these games. Then, I found I could purchase old Nintendo games for the original NES and download them directly to the Wii for $5 each. I purchased several of my old favorites, and they were all fun as well. Two games, however, have proven to be the two that I come back to often, and I don't know why.

One is Bubble Bobble. You are a dragon or something, and you have to go through levels killing enemies by encasing them in a bubble and running into them. The levels get faster, have harder bad guys, and give you less time to complete them.

The other is the original Nintendo Baseball (with came out 27 years ago, amazingly). This is the most primitive of sports home video games, and yet I find it so addictive. I play against the computer, and while I beat it more often than not, I don't feel that I've mastered it to the level I did when I was first playing it.

I've been wondering what it is specifically that is making me so hooked on these two games as opposed to all the other games I have, both old and new.