Point of fact, this actually isn't blackjack, this is a variant known as "double exposure". Basically, you see the dealer's hole card, but in exchange for that information, you face other sacrifices. Here, there is no 3-2 blackjack bonus, and you can't split or double down, and apparently in this implementation, an A-10 blackjack doesn't actually beat a 21 made of smaller cards, so even if the dealer starts with 21, you can still get a push if you manage to get to 21, and the dealer can take away your guaranteed win from blackjack by getting 21 constructed out of low cards itself.
It's a decent implementation, but don't kid yourself, if you walk into a casino, you will NOT be seeing this game anywhere, at least not like this. I'm pretty sure that the dealer is supposed to win pushes as well. You have a LOT of sacrifices for seeing the dealer's hole card if you ever see double exposure in a casino (and I think it has fallen out of fashion and doesn't exist any more anyway, or at least it is extremely rare) and this implementation doesn't have all the sacrifices you would face under real conditions built into it. I am not actually sure if the boons this game gives the player are enough to actually give the player an advantage. I played it for a good while and didn't come out ahead, but that doesn't really prove anything. I have also played real blackjack in real casinos for hundreds of hours and I'm only 1600 dollars ahead and I should be twice that, if you go by the mean. Frankly I don't understand why blackjack is still offered by casinos any more at all. It's too vulnerable, too easy to take away the house edge and get an edge yourself.
That said, this game, on its own accord, is a nice little implementation. It works fine, and it's fun to play. For a while. It is what it is and that's all that it is. The reason double exposure is out of fashion applies here though. It's too depressing. When the dealer has 20 for instance, you just have to keep hitting until you get 20 or 21 (unlikely) or bust, even if you've got 19. People want to have actual HOPE when they are dealt a 19, and they also want to have a choice, for there to be some strategy involved, not for their decisions to be dictated by a foregone conclusion with no freedom (there is nothing to think about, no uncertainty, if you have 18 and the dealer has 19, you will lose with 100% certainty if you stand so it's a really easy decision to hit - if the casino gives you a game with no strategy involved, you can be sure that it has a huge advantage no matter what you do), that's why it fell out of popularity.