His filmmaking was particularly influential, with critic Georges Sadoul considering him "one of the three major postwar Greek directors" (along with Michael Cacoyannis and Nikos Koundouros).
This, and at least one other of Armstrong's films (some stills of which have survived by being reproduced in a book by Georges Sadoul), is in white silhouette on a plain black background.
Georges Bizet | Georges Cuvier | Centre Georges Pompidou | Georges Simenon | Georges Bataille | Georges Clemenceau | Paul Georges Dieulafoy | Georges Perec | Georges Duhamel | Georges de La Tour | Georges Schwizgebel | Georges Pouchet | Georges Pompidou | Jean-Georges Vongerichten | Hurricane Georges | Georges Seurat | Georges Moustaki | Georges Méliès | Georges Jeanty | Georges Sadoul | Georges Mandel | Georges Cottier | Georges Carpentier | Georges Canguilhem | Georges Brassens | Georges Besse | Georges Vanier | Georges Duby | Georges Doriot | Georges-Charles de Heeckeren d'Anthès |
Georges Sadoul recognized Gasnier as a member of early French filmmakers known as the 'Vincennes School' which also included Gaston Velle, Georges Hatot, Lucien Nonguet, Lépine, Andre Heuré, Georges Monca and Albert Capellani.