One game that I love is Minecraft. I find the variety of gameplay options makes it a game I can come back to time and time again. Building is one of my favorite things to do in Minecraft. The mechanics involved in this include mining/breaking blocks, damage, drops, game modes, and crafting. Mining creates a challenge dynamic when trying to build because it can take time to gather all of the materials needed. Depending on the complexity of the structure being built, the materials required might be rare to find, adding an exploration aspect into the mining process.
Being in survival mode, damage is an important mechanic to consider in creating a challenge dynamic because even if I am not inherently putting myself into dangerous situations as a player, dangers can still arise. For example, mobs can come attack, or when mining you can fall a large distance or fall into lava. All of these aspects create a challenge, because no matter how many materials you have gathered, if you run out of health, you die and drop all of your collected resources. Depending on how and where you die relative to your respawn point, you may or may not be able to recollect your resources.
These mechanics and dynamics make Minecraft fun for me because I can creatively express myself through building, but still experience a challenge dynamic along the way.
