Nimble quest is an interesting game, but ultimately one I don't think is worth your time.
The game has a number of good points, it's well animated for what it is, the heros are varied and each one is distinct enough to be interesting, and the characters even gain new sprites when they level up.
But all of that is lost behind the appalling game design that stems from being made for mobiles. You can spend 'tokens' to buy large boosts to damage, speed and health for runs through the game. You can also spend them to continue your current run, but the cost doubles each time you do so, starting from one. Tokens are rare drops, you get perhaps one every five levels. So you're already stressed for tokens if you just use them as drops. However, you can buy tokens for 'gems'. Gems are your other ingame currency, which can be used to level up.
At a certain point in the game you simply need to level up and use the boosts to progress. And that means grinding. Lots and lots of grinding.
Now I'm not opposed to grinding in general. After all, playing the game is why we're here, so being forced to play the game isn't bad, of itself. The problem comes when you have to to a number of 'bad' runs without spending tokens on the boosts so that you can then do a good run in order to get to the next level and unlock the next character.
So it's a nice idea, it's a nice game, but you can smell the scent of addiction mechanics all over it. And it just isn't a good thing.
Nimble quest. Worth your money, but not your time.