This is a fun and interesting card game. I was quite engaged and played long enough to see as many features as I could. The theme was met quite well; the numbers becoming so large that they had to use exponential notation, had me writing stuff down before deciding which card to play next. Nice, simple design.
Some descriptions on the features would be nice. I was able to figure them out, but after a fair bit of experimentation and practice. I calculated the rough number of turns per round, but the number wasn't 100% consistent; I couldn't fully plan when to use certain cards (unless that was the intention). For the shop feature, I was able to figure out what I could do fairly quickly. The draw card button after the first press may be redundant, as I always clicked it to get all the cards per round so it would be worth automating it.
I found that just before the player and opponent scores use the exponential notation, the scores started wrapping. When I ran out of cards, the game wouldn't game over. Also, with the potential numbers the game could reach, is there a number that could be too much for the system to handle (could break the game)?
Overall, I quite liked it and was a nice brain teaser.