Just downloaded it. It's a very fun, simple, and addictive game. But I'll give you a fair review.
I'm a big fan of Subway Surfers. I dominated that game for like two years, had so much stocked up. Then it restarted everything on me and I had to start over. I rage quit, and I've been searching for a new game to play on my phone on a regular basis. Still searching.
Anyway this is like a football version of that. But I'll be honest while the retro look is unique and stands out, I think it comes across as lazy. And I understand your company probably doesn't have the same budget that the companies that make Temple Run and other apps like it do, but this app would be so much cooler with better graphics. It does make it stand out a little though.
Another thing I disliked was the controls. I failed my first four runs because I thought you had to slide your finger to move side to side like most other endless running games. I definitely didn't like the touch to move controls.
This game would probably be my favorite game ever if you were to ever get it to the point where it has the same graphics as a game like Temple Run or Subway Surfers. Like the field is in so much more depth and you have a better view of the runner. In Subway Surfers for example you're running through a city and the city changes (in a loop) and you dodge trains and jump barriers. It'd be so awesome if there was a football game like that where you're on the field, and the parts of the crowd/stadium change, or even like a backyard type of field that goes on and on and the outside changes. And instead of trains you're dodging defenders, and for the barriers to jump over there can be cones and step-overs. It'd be such an awesome game for football fans.
I wouldn't pay for the game you have now though, it just wouldn't be worth it. I have never paid for any app in my life, and I'm sure a lot of people are the same. If I was going to pay for an app it wouldn't be a game, it'd have to be like a very useful tool or something. So I think it would get far more attention if you just put all the attention into a free game that was supported by ads. Then have micro-transactions and an add free version available for purchase. I just think you'd get way more people willing to go for it then and get addicted that way. Like I'm pretty sure you can buy the full GTA San Andreas game for your phone and play it, for like six or seven bucks. If I was going to go through all the trouble of putting in my credit card info and all that for google play/itunes, I would rather give five extra bucks and go for that then get this app for 99 cents. Not to sound harsh.
I don't know the first thing about building and selling an app though, but I know it's not hard to know that it isn't easy. It's a really cool game and I wish you the best of luck. If you guys could somehow ever get it to the game I suggested then I would probably pay $20 bucks for it lol.