One of those games that is easy to pick up but extremely hard to master.

A great example of this are keys: You can simply pick them up and use them on doors, but it takes some time to realise you can also throw them at a door to unlock them and free up your hand to grab a weapon instead. And another example is the sword: It's easy to understand that if you slashing people with it they will die. But then you will see someone throw a sword at you and you learn that throwing them is just as deadly. Then a little bit later you might notice that you can actually hold the sword down to use as a spear and stab in front of you with it. Ingame there are many more great examples of mechanics that have more dept that you

Duck game is a great game for player who are looking for a game with a little bit of depth without that depth existing of min/maxing stats like in an RPG.