Firstly.. you run it via the Homebrew Channel... Second.. you look for... Launch Game (should be first option in the list).. then you press B to reboot... then after reboot.. you can normally run the game (without having to update)...
**FEW NOTES**
After using GeckoOS and pressing B to reboot
You can normally run games, without going to the homebrew channel (you only have to do the GeckoOs process ONCE)..
But one catch... if you pull the power plug from your wii, in other words if your wii has 0 power to it, (means no red light, no orange (or whatever color) light, and no green light).. THEN you'd have to do the GeckoOS reboot with hooks process again...
Soo.. to wrap it up
1) Homebrew Channel
2) GeckoOS
3) Press B on launch game
4) Play games normally
5) If wii has no power at all (no lights are on) then you have to reboot with hooks again
else if the wii has some type of power (any color light is on).. then you can play games normally (without updates ofcourse)..
i hope i explained this well enough.. Have FUN!!!