Sound is often converted to mono or low-bitrate HE-AAC to save space. Top Modern Compression Codecs
To reach 10 MB, resolutions are often scaled down to 320x240 or lower.
Technically, fitting a 90-minute movie into 10 MB requires a bitrate of approximately . For context, a high-quality 1080p stream usually targets 8,000–16,000 kbps .
You will likely see "blocks" (pixelation), motion blur, and a lack of fine detail.