It has some interesting mechanics, but couldn't make it to 10 cards, not sure if I was just unlucky, kept trading cards mostly. Made it to 8 cards and wasn't sure if opponents will keep spawning. The world felt interesting, just unfortunate I couldn't get to 10 to unlock the next area.
As for the engine, there is some weirdness going on. Took forever to load and in mac firefox it kept freezing my browser. Took about 2 minutes to load half freezing and half responsive.