Hello again I installed everything went fine.
But I don't understand how you guys are adding/launching screenpacks .
I tried
/home/pi........ikemen go.sh -r big
this loads ikemen fine but not the big motif . As expected
./Ikemen_GO path/to/motif/select.def
This gives me "no such file etc " error .

I am not familiar with adding screenpacks and stuff to ikemen only mugen .
Thier instructions are ./Ikemen_GO -r motif/path/select.def

I also tried my Xbox one and off brand ps3 controllers neither worked in Ikemen .
This could be solved using qjoypad before ikemen or autoloading qjoypad with same as ikemen game/motif. Thats what mugen installer on pi does layout same name as exe.
I just unaware of ikemen gos launch command. I feel thats the issue with motifs and using qjoypad .

I am also curious how we will launch more than one ikemen motif/game from a retropie .