To prevent some minor frustration, after adding a secondary genre (less serious for platform), the player should be given some sort of option to clear one of the two. The reason why this is frustrating is because even the workaround (simply canceling and creating a new game) isn’t possible with keeping a publisher deal (since canceling would fail the contract).
For example, I had a particular Publisher Deal for a Dance/Simulation game, which started out as a ‘great’ combination. I wanted to test out secondary genres, specifically Action, but as it turned out, the combination went down to ‘good’. No big deal, let me just… oh wait… I can’t switch it back?! And if I cancel now, I’ll get the penalty and I won’t get this particular deal again.
So, yeah, the frustration is a bit minor, but I would rather not have to worry about these kinds of mistakes that end up costing me something (the deal, or the overall profit for a lesser combo), simply for being curious.