I don't think it matters what angles the lines are drawn at. Isometric is just projection where no measurements are distorted due to perspective, I believe. So I would call that piece isometric. Though I could be wrong...
As for critique (which always help), I would suggest using either 1:1 or 1:2 ratios for isometric pieces so you don't end up with jagged looking lines. The black outlines in the iso piece exacerbate the jaggedness, also.
The shading on the cat is inconsistent. The green head is shaded almost as if lit from below, whilst the highlights in the eyes suggest a lightsource above. And then the poofy neck is shaded as if sort of lit from the side, sort of. You need to concentrate on the position of your lightsource(s).
The bottom one is alot better, but shading is still a little off, primarily on the feet. The palette for this piece could use some differentiation, the white and near-white yellow are too close together, I think. There's too much highlight on the tongue, also.