ProtoSans21 by Roman Gornitsky is a free pixel display font built from rigid rectangular strokes and sharply squared forms. Its blocky letters use broad verticals, flat tops, and open geometric interiors, with narrow breaks that separate key strokes and give the alphabet a cutaway, mechanical look. The construction is deliberately spare.
It is strongest in game title screens, where its low-resolution structure can become part of an interface rather than ordinary labeling, and it also suits technology branding. Album covers, event posters, and merchandise gain a direct digital-era reference from the stepped shapes and uncompromising grid throughout the entire lettering.