An okay game
Nothing really to see here. If you've played High / Low type games before, this won't blow them away or anything.
But outside of the innovativeness, I found that the "High" / "Low" buttons I had to click felt a bit confusing. Why is there an arrow pointing down on the "High" button, and an up arrow on the "Low" button? And at first I couldn't make out from the instructions whether clicking "High" meant that the top card was the high card or if the bottom card was the high card.
I'd suggest making it "Higher" and "Lower" instead and more clearly indicating which card it was talking about.
Also, you should explain what the rules for ties are and whether Ace is equivalent to "1" or "14". You find out pretty quickly when it shows up, but it's annoying to realize I was expecting that aces were high for some reason.