It’s a question of scope really - if you’re just making a local user game with pre-determined assets (like a Chess game), Blueprints is all you probably need. If you need more advanced features, like multiplayer, asset streaming, or seamless server travel - you’ll need to delve into C++ a bit. I’ve been sticking to Blueprint primarily for my prototype, but I’ve had to expose quite a few events and functions via C++ to continue. The reality is there’s a lot of advanced functionality that simply isn’t exposed in Blueprint (yet). Don’t expect to whip up a AAA title completely in Blueprint, but your typical Mobile game is probably pretty do-able.