Actually it's two lines. I do it all the time for big games and small games, usually loading the player's last save automatically.
var savefile = SharedObject.getLocal("yourgamename");
Flash seems to be a pretty awesome platform for games now, but most of the time when they're being deployed to the user through websites or whatever, you get to play them in a tiny window without any option to use your controller or change the controls, save / load and stuff - They're not convenient and I guess that's one of the bigger reasons why people won't buy that stuff. At least that's my reason if the game doesn't have something instead that it excels at (like the art direction in Samorost).
Oh, well you can turn a flash file into a .exe file and play it full screen if you want. You can change the controls in alot of games and Ed McMillen's last one could be played with a controller. I can confidently say that most iPhone games could be done in Flash- Not including the tilt sensing. If you're good at making games, you can make a good game in Flash.
You must just not like the game design
in most web games