(1) Is there any difference in the GIF encoder in Game GIF, Pro GIF / Universal?

No, the latest version of the three assets uses the same encoder.

(2) So, what's the difference regarding GIF features between Game GIF, Pro GIF, and Pro GIF Universal?

Game GIF provides the encoder and GIF managers for recording GIF. Supports instant preview the newly recorded GIF frames in the recorder in memory. With some additional optimization and enhancement compared to other GIF assets. While Pro GIF / Universal provides powerful GIF player solutions in addition to the Game GIF features, with a series of deep optimization regarding performance, memory. The Universal version boosts the decoder(player) speed up to 50%(up to 70% for some GIFs) faster than Pro GIF, the faster decoder speed is essential for some applications that highly rely on GIFs.
(* Please select the suitable package base on your application purpose)

(3) Can I upgrade to higher versions with Game GIF or Pro GIF?

You can upgrade to higher versions any time you want, with a cheaper Upgrade Price (you don't need to pay the full price of the new package).

(4) Is it suitable for Mobile application? Any performance issues?

Sure, all our assets primarily designed for running on cross-platforms.
Mobile devices like Android, iOS phones/pads are also the important platforms we support. The performance and speed are very similar on mobile and desktop platforms. 

Some tips/suggestions on using the GIF recorder & design the GIF feature: 

- Take care of the resolution(height * width) used and the framerate(FPS). All the GIF players support up to 30 FPS only, most GIFs on the Internet(e.g. use 10-15 FPS only.

- The GIF encoder(save process) and decoder support work in the background thread. 

- Let your users do something else before the saving is done. 

- Hide the saving UI until it finished, then popup, or notify the user when the file is completely saved. 

- Show another UI for displaying the GIF if you like, and let your users continue to do something with the GIF base on your design.