I was in similar situation. I didn’t know what to make! It’s better to first plan the concept. Once that’s done, you can start creating assets and creating levels. Write out all ideas for the concept that you can think of. It doesn’t matter if they are stupid, dumb or useless. Once brainstorming process is done, you can go through the list and remove the ideas that you don’t like or you think that won’t fit in. After getting the right idea, as I said above, start making assets. You shouldn’t bother yourself with ‘OMG! This looks horrible!’ and similar things. It’s important to make a prototype first, to demonstrate the concept, and then fine tune it to your needs(choose the platform etc.)
Use example projects to rocket-start your project. They help a lot!
Above was written from my experience. Good luck making games 