One concern I had before I started playing was that I might be addicted to playing many hours a day, and this would hinder my college studies. But that's not what happens and I explain the reason ...

Art: Red Dragon by @monsterwhale
This bar needs to be constantly reloaded, as it will only give you the maximum reward (for each victory in battles) when it is at 100%.
After about 20 battles it drops to 90% and it takes about 10 hours to return to the full 100% charge. This keeps you from playing hours and hours without stopping.
You can still play, but below 80% you are starting to receive substantially fewer DECs for each win, so it is desirable to wait for the bar to reload.
Another aspect is that if you wish you can spend even less time playing; using the "skip to results" feature, and going straight to the result of a battle without having to watch the action unfold. This way each battle can take less than 2 minutes, or even less than 1 minute.
Therefore, due to these two factors, you can play just half an hour a day, complete your daily mission, and get on with your other daily tasks, without harming your life and work or study routine.
As for skipping straight to the result, just one observation:
In my opinion, at least in the beginning, you should not always do this, as you will not know and understand all troop formations, that is, the possible sequences in which the cards can be placed, nor the strategies and effects that they might have.
By way of study, I find it very valid to observe the progress of the duels, but it is still possible to accelerate the speed so as not to waste so much time.
So these are some more compelling reasons why I think it's worth starting to play today! But there's more ... See you in the next article, and I hope to see you soon dueling against me!