Hi
Yes, as the person above says, it is not a joke.
But to explain the meaning of the sentence, you need to understand the subtle comparisons he is making.
1. Comparing life to a game. In this context, game does not suggest a serious competition. This suggests that a person approaches their life in a non-serious manner. "He treated his life in the same way as a person might treat a friendly game of football - as if the outcome was not as important as the enjoyment of it.
2. Comparing the Cricket to life. Cricket is a sport, and while it is taken seriously, it is still a form of recreation. Life can happen without cricket but Cricket cannot happen without life. Therefore, Cricket is less important than life; .
3. Comparing British to Europeans. The most obvious comparison in the sentence. He is saying that British people do not treat life as a game, but Europeans do.
The real point of the sentence is saying that the British have an advantage over the Europeans. Because they are taking life seriously, and the Europeans are not, that they will be more successful at life. To me this implies that the British will be in competition with the Europeans, which is contradictory, because that means that Life, is in fact a game - it is just a more serious game than sport.
There is much meaning in this sentence, which is why it would be quoted in this manner. I don't know George Mikes, nor do I necessarily agree with the statement but it is skillfully worded.