I'm going to make a basically vanilla Frogger, as far as gameplay. I'm completely out of practice in pretty much every aspect of gamedev, but I'd like to focus on my art skills at the moment (because I've been getting the feeling that I may enjoy that the most). That said, a few years since seriously drawing anything, I've sketched (well, it took a few hours) what I'd like the contents of the game to look like.

...if I can.

I consider myself way more proficient in producing (low-poly) 3d models, so it's going to be a 3D game, in Unity. Because I also need a refresher on Unity.

You'll notice the... perspective of the drawing. I thought I'd make a faithful to the original, isometric game, but after some experimentation in the editor, I think I have to go with a more normal 3rd person view. I can't - and don't want to spend time trying to - figure out how to make an isometric view look good.

Oh, yeah, I suppose most people spend valuable mental resources on something other than frivolous concept sketches. Don't worry, I've been prototyping a little, too.  

Well, had to start with remembering how to animate in Unity.