Pretty straightforward - can "Snap" packages use the dedicated (NVIDIA) GPU in my laptop?
For example, if I download a game via a "Snap" package (e.g. "SuperTuxKart"), will it use the GPU, or will I need to download the "traditional" package instead?
Yes, snap package can use the GPU. To check whether a snap package has access to GPU acceleration, run the following command. Assuming you want to check for chromium, you can see that the snap package has been configured to use GPU acceleration.
For the case of chromium, you can test with WebGL demo pages.