if there is moisture coming thru the concrete, there was no plastic vapor barrier installed when the floor was poured.if that is the case, cement a 6 mil layer of plastic to the existing, "uneven" floor and cover with a 1/2-1 inch layer of cement or thinset. this can then be covered with the desired flooring of tile, carpet, etc. one thing to consider for walking comfort is the cork tile. it is resilient and a fairly good insulator. JMHO