Hero Hunters District 4 can be a difficult venture if your under leveled or have a weak team. They way this game is set up is the developers have made many of the later stages very difficult in hopes that you will spend real money on the app. You can say that it might not even be a game the way it’s set up as your going to be manipulated into buying something that wont get you ahead that much so you have to buy even more.
If your really into this app for some reason and are planning on spending money there are a couple things that can help you out. First of the piggy bank can give you a large bonus when you make a purchase. The extra amount earned seems to decrease as you purchase more though so be warned encase you start to go crazy spending. This is a good tactic to earn extra gold in the beginning of the game.
The second thing that you can do to stay ahead is purchase hero crates from the store using gold. These can be a great source of new characters and you wont have to worry about collecting all those fragments to put one together. Of course, if you trying for the best heroes using the crates you chances are probably going to be pretty low. So it might be a good idea to work towards the stronger ones collecting fragments while you hope for the best using crates.
If you take you time moving forwards as things are probably going to be slow going as this is how the game is designed, you will eventually be able to get past what ever hurdle the have put in the app. Just a far warning though, this app is designed to get you to play as long as possible so that you will hopefully start to throw money at it. So if it seem sway to difficult or time consuming this is to manipulate you into spending real money. In a lot of ways apps like these real aren’t games, but traps to generate an income.
If your interested in more related info you can check out the Hero Hunters Wiki.