I bodge repaired my rough, uneven and crappy concrete workshop floor when I knocked an internal wall out into a garage, the garage didn't have any floor at all, bare earth, so I was left with a step to fill. All of the realistic options involved removing a huge amount of concrete and replacing it again, which I didn't have the time or money for, so i over-boarded it all with chipboard dot and dabbed with concrete.
Anyway, over the chipboard i used vinyl flooring, I picked up a load of decent sized end of rolls and laid them darkest to lightest across the space for the cost of a tank of petrol. It's great stuff to work on hasn't marked at all from the mini and oil drips just wipe up. A good option if you can't afford porcelain tiles!