Once I got the hang of it, I enjoyed the 1v1 combat game system. However, the onboarding was tough, since there are too many critters / effects to memorize off-the-bat, so a good few minutes is spent losing playthroughs, and referring back to the how-to guide to see what the critters actually do.
Do feel that there's a balancing issue, and that the first (and presumably only?) level is way too hard off-the-bat. Not only is the enemy AI much more skilled at getting better critters than you, but it also seems to heal at a constant rate.
Gameplay would be improved if there are a few "gimme" levels at the beginning with very limited power-ups and either tooltips or a referable in-game guide as to what the critter does. But aside, I think the game design is quite good, the art + sound are complimentary to each other, and once refined, this will be a fun combat game!