Like the other language versions in this series, the games are excellent for learning vocabulary in Latvian. Work through them systematically and you won't be stuck for a word on a trip to Latvia.
BUT you also won't be able to string words together in sentences, if this is all you're using. True, there are some phrases included, but mostly this is about learning lists of related words such as food items, colours and so on.
If you're just learning the basics for a holiday, this is perfect - but if you're more serious about learning Latvian, consider buying it as part of a wider selection of material.