I've never been very interested in the normal Football Manager games because despite being a very logical person I always get a bit lost in it but this takes out all the irrelevant features and puts all the good stuff into an amazing game that I can play anywhere!
It's great without buying anything else. I personally like creating my own squad then adding them into a league and controlling them.
However, I have bought the 'Unsackable' unlockable so I can rebuild with squads without getting sacked when results don't go my way. And I did a career with Cardiff where I filled their team with 1 star San Marino players and took them all the way down to the bottom of the Skrill South before changing to highflying Barrow and getting promoted to the Football League. Only problem was I was getting sell on fees from the young Cardiff players that I'd sold so I was getting millions for doing absolutely nothing. Despite the major glitch, it actually made the game even more interesting and I'm now a top half League One team with a good, balanced squad.