It's F2P MTG and it's a pretty good version of it. It lacks key features that older clients had years ago and isn't the most stable but the mechanics are well implemented and it's not at all Pay-to-win, atleast no more pay-to-win than real MTG, you earn coins to buy packs at a pretty quick rate and there's plenty of promo codes online to get free unlocks, I've not spent a single cent on this game but have several decks I enjoy running.
I'd really recommend this for new players to MTG as the tutorial is decent but regular play gets you used to the rules of each card since you don't have to doubt whether something is a legal move or not, if the card is highlighted then you can use it and the game will explain how, it's probably the fastest way to learn MTG.
There are two issues that annoy me about this though:
1. Time-outs; I play decks that the community as a whole tend to hate, mostly mill (because I don't care what you think it's fun) and this can frustrate people, so instead of accepting a loss and forfeiting or playing on, people will run down their timer until the end of the game. The timers are way too generous and there's nothing stopping a player from letting it run to a sliver left then proceeding with no punishment. They need to allow for a single time-out and they need to force it to start sooner in my opinion.
2. The meta. White lifegain decks are the most annoying decks to play against because they rely on synergies and stacks, more often than not upwards of 20+ synergies can be initiated in a turn that turn into one big feedback loop. This wouldn't be an issue if it weren't for the fact players need to press the proceed button for each step. I've had games last 60+ minutes because I'm fighting lifegain where the opponent needs to confirm up to 100+ abilities in their step with no way to speed it up. What's especially annoying is that the default white deck encourages this kind of playstyle that grinds the game to a stop and sucks all the fun out. Lifegain is fine albeit predictable and boring, wasting everyone's time isn't. The same thing applies to any deck that swarms you with ability confirms but white lifegain by far is the most common.
I also wish that WOTC would include more deck codes with their products so you could transfer your physical cards into Arena, I've had one MTG product in the past with this and it was fantastic but knowing WOTC they wouldn't bother making this standard across their products.
I'd really recommend this for new players to MTG as the tutorial is decent but regular play gets you used to the rules of each card since you don't have to doubt whether something is a legal move or not, if the card is highlighted then you can use it and the game will explain how, it's probably the fastest way to learn MTG.
There are two issues that annoy me about this though:
1. Time-outs; I play decks that the community as a whole tend to hate, mostly mill (because I don't care what you think it's fun) and this can frustrate people, so instead of accepting a loss and forfeiting or playing on, people will run down their timer until the end of the game. The timers are way too generous and there's nothing stopping a player from letting it run to a sliver left then proceeding with no punishment. They need to allow for a single time-out and they need to force it to start sooner in my opinion.
2. The meta. White lifegain decks are the most annoying decks to play against because they rely on synergies and stacks, more often than not upwards of 20+ synergies can be initiated in a turn that turn into one big feedback loop. This wouldn't be an issue if it weren't for the fact players need to press the proceed button for each step. I've had games last 60+ minutes because I'm fighting lifegain where the opponent needs to confirm up to 100+ abilities in their step with no way to speed it up. What's especially annoying is that the default white deck encourages this kind of playstyle that grinds the game to a stop and sucks all the fun out. Lifegain is fine albeit predictable and boring, wasting everyone's time isn't. The same thing applies to any deck that swarms you with ability confirms but white lifegain by far is the most common.
I also wish that WOTC would include more deck codes with their products so you could transfer your physical cards into Arena, I've had one MTG product in the past with this and it was fantastic but knowing WOTC they wouldn't bother making this standard across their products.