Trials

Trials are unlocked after you complete Chapter 2 - City Park. Basically Trials are a rerun of the same level but a bit harder and sometimes with different bosses.

The other is that usually the chests don't contain gold. You complete the trials in order to gain rewards and EXP and also to get special items that are not obtainable in other game modes such as Gold DNA which are used for some key evolution upgrades.

Some of the trials are significantly more difficult that the standard levels, so you may need to grind a bit and be prepared to try a few times before getting some of third stage trials done.

But you should aim to complete the Trials because of the rewards that you get are very useful in generally leveling up your character for the whole game.

Do the Trials!

You probably won't be able to get through the chapters without grinding through all of the accompanying trials. We really do recommend that you hit up the trials associated with the level that you completed before trying out the next chapter in the main game.

You'll get some great rewards and also the special Gold DNA coin that you can only get from completing trials to make some upgrades to your character in the game and fill some achievements.