So, basically you click the big download button, that will take you to a page where you can pay what you want or continue to the downloads.
There, you download the version that fits your computer operating system (Windows, Mac or Linux).
It will be a packed file you have to unpack somewhere on your computer (usually via just double-clicking it and selecting a folder it can upack to).
Inside the folder with the unpacked contents, you'll find a file with a Quidget icon (the orange dog) that's called 'Quidget the Wonderwiener'.
Double click on that and the game starts!
If that's too complicated and you don't mind a few naughty extra scenes, you can play it here:
without any hassle in your web browser ;)
Stay funky and let me know if everything went well,