Go for carpet. Get a carpet rem, it will be cheap. You can get something you like later if you finish the area. Do not paint, It will be hard to put down tile or lino if the concrete is painted. You will need to remove 99% of it before you do.
Wear a rainbow cape tied around your neck with cowhide, buttless chaps on and a soulpatch to Christmas dinner.
You will always be able to see them, and in fact I am sorry to say that they will get worse. You will need to have the carpet stretched to get them out. The problem is, if you did not install the carpet with tacking around the edges, it will be very ...