Thanks to the emulation community, these physical multi-carts have been "dumped" into ROM files. When you search for a 400-in-1 NES ROM download, you are usually looking for a single .NES file that acts as a menu system, leading to hundreds of smaller game ROMs embedded within.
If you fire up one of these ROMs expecting 400 distinct, high-quality titles, you are in for a surprise. The "400-in-1" count was a marketing gimmick. Typically, the list breaks down as follows: 400-in-1 Nes Rom Download
Searching for "400-in-1 NES ROM download" is a minefield of pop-up ads, fake "download.exe" files, and malicious links. Never download an .EXE file. A true NES ROM is a .NES, .ZIP, or .7z file. The "400-in-1" count was a marketing gimmick
Avoid these red flags: