Great game, just some suggestions for improvements:
1. Allow for more influence on the course of game
2. Include champions league & national teams
3. Add ways to keep game challenging (not randomly unfair) after maxing all skills and items
4. Make the hierarchy of leagues and clubs easier to see
5. Reduce number of clicks after a match (star man, etc)
6. Allow for options
7. Allow customized training in arcade mode
This is how I got all but the 10-seasons stars in 6 seasons:
1. if you get a better offer from a club: switch! you need the money in the first 4-5 years. while you are still low on skills, focus on passing.
2. build skills! pow and vis, then tech then free kicks and finally pace. buy simple nrg drinks. play-train-drink-train is the cycle. the coach will barely put you in 1st team, sometimes even substitute, but you get your salary anyway. go double-heart but dont let the relations drop too low.
3. once you have all skills above 50 buy the skill nrg drinks to fill the blanks.
4. buy all luxury items, houses then gadgets then transports.
5. sign with best possible club of the highest division. you start most of your games with complete nrg, so go triple-heart and use nrg drink in the break if the result is close. win a lot.
6. for the relation stars use the mini games. rest of the stars will come pretty much on their own.