Tale of two games. Croatia - Mexico is a very very close contest, while Brazil - Cameroon is the single most lopsided contest so far. 538 published a very detailed analysis here of all the potential advancement scenarios, but the simple summary is Mexico advance if they draw or win, and Croatia advance if they win. Brazil is advancing (very very probably).
This post has a little more on how the win probability graphs work
This post has a little more on how the heat maps work