http://www.retrousb.com/product_info.php?cPath=30&products_id=111 I tried out the homebrew game found at that link. It works fine in bsnes, so I assume it should also work fine on the Everdrive. However, it gives me a blank screen. The header information suggests it is lo-rom, which is probably correct.
Find out if they are supposed to work on real hardware. Often not. In my days of GBA homebrew I had demos that worked on emulators but not on hardware. I figured out it was when I would use DMA back to back and didn't allow time for the DMA to start and latch the source/dest regs, so I was clobbering the data while DMA was trying to read the registers and locking up the bus. Inserting two NOPS before trying to use the DMA again or un-inlining my transfer code inserted enough delay to make it work on a Flash Advance card
Ofcourse it works on real hardware, he linked where you buy the cartridge. If it doesn't work on the EverDrive, chances are it's loading up incorrectly for some reason. Either it's not loading it as LoROM or HiROM properly, or the ROM size may not be right, possible also if it uses SRAM maybe the setting isn't right. I believe you have the option to force various loading options. You could try forces HiROM or LoROM and see if that helps.
