Well the way that worked in the original was that if you didn't have the joystick turned when you came up to a corner you missed the turn, made things very frantic... Power pills hmmm with your game they should probably be set so you can pick them up but not have to use them until you want to, but only be able to carry one at a time, so that they are very "precious". It would give you one chance to escape a ghost, and eat him too, scoring extra points. The ghosts respawn in a kind of ghost bank somewhere in the level, and that's a place you don't wanna find yourself in! if you made the ghost bank you could make it ultra creepy, but I think I'm making too many suggestions now... Goes to show that it's an inspiring thing.
In the original there were 4 pills to a level but your game has quite different gameplay, maybe one is enough. As far as the turning goes I don't think it matters, just trying to let you know what I remember from the game.
Do you have the original pacman? Just curious.
ZX Spectrum 48k Issue 3, Radio shack Tape drive, Rank arena 12" T.V. set.