Is Cs2O2 a ionic compound, Covalent compound, or Acid

It's a bit more complicated than that:

In he structure, the two oxygen atoms are single bonded to each other and are bonded to one cesium atom each. The oxygen-oxygen bond is covalent (electrons shard), but the oxygen-cesium bond is ionic (electrons transferred from cesium to oxygen). This would be classified as ionic, but it's not exactly that.