In this Youtube Video, I test three methods in the attempt to see if it is possible to use a Game Boy Advance as an input method when paired with a Gamecube controller adapter and a GBA - GCN cable.
I did this test on the latest Nintendo Switch Update as of the making of this video which was update 19.0.1
GBA as Controller rom for flashcarts hosted from GBA Temp (you click the yellow download button off to the right side of the screen): https://gbatemp.net/download/gba-as-controller.38392/
Timestamps
0:00 Channel intro
0:02 Video introduction
0:19 Explanation of video idea
0:38 Method 1 (simply plugging in the GBA with its adapter)
1:06 Method 2 (Gamecube method)
2:51 How this works
3:06 Method 3 (Flashcart method) (Best method)
4:18 App overview and menus
4:57 How you know the GBA as Controller rom is active
5:13 Reiterating why this is beneficial over the Gamecube method
5:20 Explaining the main idea of the rest of the video
5:49 Animal Crossing New Horizons
7:29 Super Smash Bros Ultimate
14:30 Mario Kart 8 Deluxe
19:43 How awkward Super Mario 3D All Stars might be
20:33 Super Mario 3D All Stars: Super Mario 64
23:52 Super Mario 3D All Stars: Super Mario Sunshine
24:45 Configuring my controls to switch nozzle modes with my GBA
25:30 Proving it works
25:37 Super Mario Sunshine continued
33:53 Super Mario Galaxy (not ideal)
36:41 The problems with playing Super Mario Galaxy with the GBA
36:54 How I tried to mitigate this issue and finish a level
38:53 The most practical use case for this set up
42:12 F-Zero 99
45:21 Bonus content: Controlling my Nintendo Switch with my Gamecube
45:51 What this set up would look like
47:29 Super Smash Bros Ultimate one last time
51:54 Outro