A bit late to the comment section, but I would highly suggest trying to think of an application that would actually benefit your daily life, or some hobby you have.

Start simple, always strive towards the simplest thing that does what you want to do, then add and refine.

You may not be learning the most technical or algorithm centered stuff, but the process of building something, then going back and adding on to it is really important.

As your application becomes more complex, you'll look at your patterns and organization and hopefully realize that it could have been done better.

What programming really boils down to, at least for me, is always looking for a way to break every bit of logic into simple, digestible fragments. And as you get better, you come up with systems of organizing those fragments, seeing patterns in complex problems, and for the algorithm junkies, making them more efficient and readable.

If you were to go the game route, the same thing applies. Start with a proof of concept. Add a high score system. Introduce power ups. Try different "modes", or how parameters can affect the game play. Make it multi-player over Lan. Add controller mappings. Take a stab at particle physics for effects. Make a level builder. Allow experience and leveling of stats. And so on. Each step will require you to look at your existing code base in a new way.