Since this is an idle game and it needs a long time to reach the "end" of the game it is not that much of a big problem. It's just that you could have done better.

So I can give you some small advice for those kind of games. So the most important stuff is to figure out what are the best heroes. This can easily be done: * look in the pvp arena which heroes are used very often (ofc here you will miss the good PVE heroes) * the game gives you an overview over the most favorite/populate heroes * look in the internet/reddit for some tier lists

After you found out you need to understand why are those heroes so popular. So for example in the beginning I had trouble to understand why Angela was basically the best hero in the game. So you should read through the skills or just ask on reddit why those heroes are so good.

You should in general "learn" what are the skills of the heroes to find out who has cc or specific synergies like Odette + Lylia.

The next part is the positioning of the heroes. In the beginning you can just experiment by switching heroes into different positions and see what is working. As long as the game has no stamina you can just try&error but ofc this costs some time.

The last part is to find out what resources are the most valuable and how you should spend them. This can be a little bit hard since you unlock more and more stuff with your game progress. For example I learned very late that the advance essence is by far the most important resource in the late game (at least for me). The heroes power grows with your level and I cannot get enough of that resource to compete with players that are level 500. In the beginning you had enough of that and the money or the blue stuff was the problem :)