There are two places where you can upload your logo in Self-Paced games: the Player App and the Leaderboard.
Player App
To upload a logo to the Player App login screen, follow these steps:
Click the Edit button on your game
Head over to the Theme tab
Click on the Edit button for your Player App screen
Upload your logo by clicking the Choose File button and browsing your computer
Once you've uploaded it, make sure to scroll down and click on the Update button. Your logo will be centered automatically and positioned right above the title on the login screen for the Player App.
Leaderboard
To upload a logo to the Leaderboard screen, follow these steps:
Click the Edit button on your game
Head over to the Theme tab
Click on the Edit button for your Leaderboard screen
Upload your logo by clicking the Choose File button and browsing your computer
The Position of the logo is determined in terms of pixels from top to bottom (Top section) and from left to right (Left section). All logos are set to be placed on the upper-right side of the screen by default. You can try out different Top and Left values until you find the ones that better match your layout.
The very center of the Leaderboard screen is at Left 960, Top 540.
Size is also determined by pixels, and it's best if you adjust this number to your logo's dimensions. If you don't know your logo's dimensions, you can open your logo's containing folder and hover your cursor over it.
In this example, we've set the following parameters for the logo to fit in the right place:
And this is how it looks:
Once you're done, remember to scroll down and click on the Save Configuration button!