Experience:
You must try to get as much experience as possible to survive the later
levels of the game. Buy experience points in between levels, unless you have
to spend it on other things to survive. Also, always destroy all monsters in
the level. Try to get to level 10 by the end of the game.
Food:
Save your money and do not buy too much food. If you are skilled, can
complete the first three levels before becoming hungry. Also, find the food
hidden in the levels rather than buying it.