Switch games for less than 20 euro for two?

I would like to get my friend a Nintendo Switch game for Christmas. Should cost less than 20 euro and be an online game, so to speak, so that I could play it with him when I buy it too. Does anyone have a good recommendation? If the whole thing is only available at KeyStores for less than 20 euro, that's no problem. Thanks in advance for all the answers and recommendations.

If you prefer to buy a game through instant gaming, almost all games are discounted by 80%.

Unfortunately mostly not even for 1-2 euro: /