Snake: add a turn queue (up to 4 pending direction changes) so rapid key
presses are never lost, and raise base speed from 70->130 px/sec
(~128ms -> ~69ms per step) for snappier, more responsive play. Progressive
difficulty (+1 px/sec per 5 food) is unchanged.
Tetris: replace solid-green blocks with Gameboy-style 4-shade beveled cells
(pale top/left highlight, medium body, dark bottom/right shadow). Settled
blocks use C_GB_MED, the active piece uses C_GB_LIGHT, and the next-piece
preview is beveled too.
Luxferre
0abf305dff