I'm tempted to give 5 stars because I enjoyed the show so much but we were also able to get all our tickets for free so that could be a biasing factor. But if you've never seen Zarkana before and/or have never seen a Cirque Du Soleil performance, I HIGHLY recommend this show, discounted or not!
There's supposedly a storyline but I completely missed it and I'm not sure if it elevates the show in any way. Unlike KA, which seems to have a more coherent storyline, Zarkana is hodgepodge of different classic CDS feats as well as some standout individual artists. Almost every main act was a highlight for me but the woman doing the sand art was especially remarkable. The live music and singer were also impressive; I like the soundtrack so much that I'm thinking of buying it!
In terms of costume design and choreography, KA is probably better and more original (the hamster wheel act with the jump rope and the tripping drama can be seen in both shows but I believe KA had it first) but ultimately, Zarkana was more entertaining to me and had shorter transition times between main acts. Some of the transition performances were pretty funny too! Overall, a wonderful blend of comedy and art in all its forms.