My suggestion is to add an option for Risk Solitaire. I play the traditional risk game against the computer. But, I would like to suggest some additional features. First, if I lose, I would like to play the same game again with the same starting board. Part of the challenge is to win every starting configuration. Second, I suggest keeping track of the total moves that I played to see the quickest I won - this might be done by measuring turns and measuring how many lands I conquered to win (noting that I might own a land, lose it and win it back which would be that this one land was conquered twice). Third, maybe have a won/loss record.
Having said this, Risk is really well done.