To simplify things, many consoles have started to support game engines, which makes it easier to develop games for PC & make console ports.
For the Wii, the only game engine that's still available is ShiVa ($200 + Tax for a Basic License, $1,000 + Tax for an Advanced License).
If you're willing to be a bit more flexible with the console (Wii U, Switch, PS3/4, XBox 360 / One, PC, Mobile, ect.), you can utilize one of the more freely available game engines like Unity, Unreal or CryEngine. Each of these engines can be downloaded & use to design your game. The only costs involved is when you try to profit from your creation...
With the Unity Engine, you have to start paying for the engine by upgrading to "Plus" if your annual revenue exceeds $100,000. If you exceed $200,000 in a year, you have to upgrade to "Pro" to stay legal as part of their license agreement.
With the Unreal Engine, you'll have to pay a 5% royalty on any revenue exceeding $3,000 per quarter (as part of their license agreement).
With the CryEngine, you'll have to pay a 5% royalty on any revenue exceeding $5,000 per year (as part of their license agreement).
You'll have to take a fair amount of time to learn these engines to properly create your desired game in them, but you don't have to worry about costs until you're ready to monetize your game(s). Just do an actual reasonable job (& not attempt a lazy asset flip) in creating your game & you should be OK.