Rules in a tie are:
1. goal difference
2. number of goals scored
3. direct result
4. goal difference in direct result
5. number of goals in direct result
6. Lucky draw
I guess 4/5 is only if more than one team is equal after 3. Lucky draw means a lottery.
If France beat Denmark with one goal, they'd both have a tie in their goal difference, but Denmark would have scored more goals.
So yes, France must beat them with at least two goals more. Even if Senegall lost high to Uruguay, then Uruguay could still advance in stead of France.
And I wouldn't rule out Cameroun beating Germany, either. It's a bit sorry, but our players aren't the kind that run their a$$es off. So if Cameroun fights, they have a chance. They are technically more adept, and also faster, I think.
Berandor