In addition to the still-being-developed FlashyOnlineGames.com site, I also own MarioSonicGames.com, which is a long-standing and very popular site dedicated to Super Mario Bros. and Sonic the Hedgehog (plus other Nintendo and Sega) online games.
I have had a number of games made exclusively for that site, the first one of which was Super Mario Brothers: Paper Mario World, which was made in conjunction with Newgrounds.
It is a Flash version of the classic "Paper Mario" and "Super Paper Mario" RPG/platforming hybrid games, also incorporating some elements of "Super Mario World". In the game you can use Mario's hammer to crush enemies, or jump on them to kill them in the traditional way. There are 30 very challenging mini-levels to complete, with bonuses to unlock and hidden secrets to find.
(You can also play it at Newgrounds.)