I got into a state a couple times where I didn't seem to be able to play summons from my hand. Spells seemed to consistently work fine, but I was never able to finish a battle as a result of never having anyone on the field to really do the work.
The art is quite cool and really does evoke some of the old-school early MtG designs for me.
I'm a pretty slow reader so a LOT of the mechanics from some of the summons triggering effects almost completely flew by me due to how fast the text reads out when the cards are played. It does give you that feeling of playing against a player that knows solidly more about the game than you do and you're just trying to process things on the fly as they happen, but it also just highlights the massive value that tooltips on the various mechanic can bring so that players can review what just happened at their own pace.