The Sega Master System is quickly becoming like other retro consoles with new titles being found and released with each passing week. Mopiranger is a cross between Pac-Man and Pengo, originally an MSX game that was ported by Korean developers. Enemies turn to blocks when defeated which complicates things in later levels.
Seriously, if you are bored with the game play of Pac-Man, check out Mopiranger for a definite challenge increase in the maze genre. The graphics are cutesy but that is to be expected (cartoony is easier to produce with limited graphics). To me, the main character looks like the Hamburger Helper mascot, that walking/talking glove guy.
Grab Mopiranger over at the SMS Power website while you can.