Sure making a website or app you have to consider frontend + backend, but with game development there are many parts that you have to spend time on (or at least make thoughtful decisions to de-prioritize). 3D modeling and shaders or 2D graphics and sprites, physics, game logic, sound, networking, serialization / persistence, character animations, story, particles / fx, lighting and post-processing, music...you can find all these different areas you may want or need to spend time with. For a AAA game there are entire teams and functions that spend years on just one chunk of this. Teams and budgets are more like movie budgets than app or website budgets for a reason. Sticking to 2D can help a lot. As can sticking to singleplayer. As can starting with a simple and well-trodden genre. To create Tetris you obviously don't need all of these, but it's easy to come up with an idea that seems achievable at first glance to a novice but quickly realize you underestimated the project even dramatically more than web or mobile app or desktop app developers often do because there are yet more components that take real hours of work with games.
RE: engines and technologies, you have to determine if you want to create a 2D or 3D game, if networking / multiplayer matters, what platform you are targeting, and a few other things before you choose an engine.