@fourteencoast

You should read this first because we would need more information before we could actually help you:
https://retropie.org.uk/forum/topic/3/read-this-first

Also have a look at this thread and maybe it will help you:
https://retropie.org.uk/forum/topic/3120/problems-with-dreamcast-and-ps3-wired-controller/2

@mike8906 said in Unable to start metal slug 3, 4, 5 rom - Raspberry PI 3, Retropie 4.0.2:

Is it realted to the limitation of the Raspberry Pi3? Or can it be fixed?
I use a memory split of 320 as advised in one of the retropie setup tutorial.
Does the game really requires so much power that it slows down while lots of explosions/enemies appear on the screen?

From the RGUI menu you can "overclock" the NeoGeo. I did that and it works perfectly. I heard that on the original console it lagged too, it's not really the RPi's fault. Still that game is freaking addictive and one of my favorite arcade games.

@edmaul69 that's the problem. I did an update and forgot to add the bios, and had the exact same issue with CTR. Just add the bios and you will be racing!

I do confirm issue with the deletion of the kick roms is now gone (either via binary or source options). Yet I still having issue with the controls. I'll keep checking in the coming days to see if upstream got fixes. Though the binary option from RP doesn't help and I'm really puzzled by that.

I'll give another look soon. THANKS.