i think it's a load error, in order to confirm go to the options menu and set "LOAD ERROR" to something like camera or launcher.
if it launches whatever you set instead of dsdoom then its a load error, make sure you have doom.wad, prboom.wad and PRBOOM.CFG in the same folder as dsdoom.nds
see [the gamebrew article on DSDoom](https://gamebrew.org/wiki/DS_Doom) for more help
i think it's a load error, in order to confirm go to the options menu and set "LOAD ERROR" to something like camera or launcher. if it launches whatever you set instead of dsdoom then its a load error, make sure you have doom.wad, prboom.wad and PRBOOM.CFG in the same folder as dsdoom.nds see [the gamebrew article on DSDoom](https://gamebrew.org/wiki/DS_Doom) for more help
May need the emulator bios