If you're not interested in using your smartwatch for the general and somewhat boring text message notifications, email updates and general fitness applications, why not try out the popular game Flappy Bird?
Providing your device is running Android Wear, all you need to do is download this modified APK and run a few commands through your PC to have access to this addictive side-scroller.
Alongside pushing applications like Flappy Bird, you can also do some nifty things including running Windows 95 on your watch - if you for some reason feel the need.
As the game isn't optimized for this platform, expect your score and parts of poles to be cut off thanks to screen limitations - however the main part of the game is still perfectly functional. If you're bored with not much to do, this seems like a pretty nifty trick - but it's still not convincing enough for me to purchase a smartwatch for my own use.