Working on the icons of Follix (another game I'm about to release soon), convinced me to add icons also for the floppy disk and the manual of MeMO. This triggered yet another update...

v3.13 (26.6.2021)
* Fixed a (seemingly innocuous) bug (an OR instruction in place of a MOVE instruction) in card matching code.
* Improved card matching policy by considering it a mistake also when the second card flipped had already been flipped before, even if the first card has been flipped just once and/or its twin card has not been flipped yet.
* Made a couple of tiny optimizations.
* Changed design of 'M' and 'N' letters (they were basically lowercase, which was inconsistent, as the only lowercase letter was supposed to be the 'e' in "MeMO").
* Changed alignment of logo in menu screen by 1 pixel right/down.
* Adapted to and built against latest custom framework.
* Reworked game icon.
* Added floppy disk and manual icons.
* Improved/extended manual.