Well, I kinda like current loading screen.
Maybe keep it as fall-back option (i.e. if using custom track or the track has no screenshot yet)?
Anyways, I don't like any of the screenshot-based examples so far, but I like the basic idea.
The raw screenshots serve poorly as a background. They need to be desaturated a lot and have a much lower contrast. Overall, they should be just a really subtle background IMO.
Also, the screenshot quality itself is low. There is a clearly visible aliasing. I think the screenshot should be taken of a game scene taken at the highest quality level. Anti-aliasing is a must.
About the “World Kart League” thing: Well, it is an interesting logo, certainly, but it doesn't fit at all to the existing logo in style. It would only make sense of the official STK logo is changed as well.
I also agree the text “World Kart League” does not make much sense.
There is no such thing as a World Kart League, neither in the real world, nor in the fictional world of STK. And STK is lacking any sort of an actual “League” or “Championship” mode. There are also zero references to such a thing throughout the game, so it just does not fit at the moment.
Back to the loading screen:
Maybe also include additional information about the upcoming race:
- Track name
- Track direction
- Race type
- Total number of karts
- If normal race or time-trial race: Number of laps
But to be honest, I don't thing any of this loading-screen stuff is really that important and high-priority. It's nice to have, but I don't care much about it.