Realistically speaking, way too many DS games were shovelware games. If you focus on just the best of the best, the most you will take up is a little over 16GB. If you trim the ROMs (which I did using akAIO,) you can fit almost double that on the same amount of space. Even the largest DS game is only half a GB and there aren't many that size, most are about 32MB to 128MB. Simply put, it's unlikely you will ever fill that 32GB.