Obviously you cant do much wrong on a free to play game, but waste your time.
Thanks to short game length you do not need much time to figure out how much fun the game is to you, so it might be worth a try.
Still, there are certain aspects that make the game way less entertaining than other card games, which is the main reason i do not recommend it:
1.) You draw 5 cards and select 2 of them to play. Each turn you draw 5 new cards.
This leads to a situation where you cannot plan your next step, since you do not know which 5 cards you will draw next. This game mechanic drastically reduces strategic options in this game.
2.) The 2 cards you play level up. After a certain amount of turns you have access to the leveled cards. Additionally, there are many cards that can snowball within a single turn. If you are simply unlucky not drawing your leveled cards ( or a viable counter), your opponent can snowball to an unbeatable situation quite quickly. This increases the RNG factor a lot, which is quite negative for a card game that already has a lot of RNG.
3.) While this game is not actually pay 2 win (as you can get all cards for free over time), there are certain cards that are clearly better in all aspects compared to some of the cards you start with. Some cards are even unbeatable by the starting decks. Additionally the amount of free cards you can earn per day is limited.
The game is much less enjoyable if you do not pay for it or grind for weeks to get the cards you need for a solid deck.
So in the end.. it offers less strategy than other trading card games and is less casual as well, making other games clearly better.