This PC game was around the same time of the Keen series when I was playing.
There are monsters locked up in a tower and you are a monk who is put into the tower to kill all the monsters. You kill the monster by shooting herbs at them that you pick up along the way or jumping on the monsters. Herbs are like clovers and red stuff I can't remember and many others. The monk wears sandals and the floor plan is made out of squares. so you can only walk up down left right not diagonal.
Some of the monsters: a largish blue spider, a monster that looks like a red umbrella.
You can teleport and you can puch things around. You can also turn on/off light switches by moving your entire body infront of the light switch and pressing up ro down.
You must drink and eat to keep your health up.
You can also become poisoned and your screen will shake. time will fix this
You can also become invisible to the monsters for a limited of them if you get the right elixir.
im sorry that is all i can remember.
I really do hope some one can help me