In comparison, it's a concrete task. There's pretty much no rules when it comes to making a game. Versus with an engine, you at least have some requirements an

In comparison, it's a concrete task. There's pretty much no rules when it comes to making a game. Versus with an engine, you at least have some requirements and guidelines. It's gotta render stuff, do physics, etc. With a game you could literally do anything, and 99.99% of all stuff you can do probably sucks and isn't fun. So you have to really be willing to throw ideas away.