Overall, it's decent

If you've played games of this type before, you'll adapt quickly. I personally had a lot of fun playing it. There aren't really any tips, but while characters are important in this game, the key is who can create Super Merges faster and more often, so you need to combine them carefully. If you focus on that, you'll achieve a decent win rate. To get a Super Merge, you need to be level 20 or higher. To do that efficiently without waste, you should gather them in one place and perform the merge operations. For your reference, I didn't get any hidden quests.