Without wishing to dodge the question it would help to to know what type of flooring that you want to replace/cover the existing floor with.
Assuming that you dont want to go to the trouble of removing the existing tiled flooring you could lay other tiling,vinyl or laminate/wood for example on top. One of the things to consider is the height that these various coverings will come up against existing kitchen units/skirting. You may also need to shave off the bottom of any room doors so that the new covering doesn't stop these doors opening/moving.
Hope this helps.