What do you mean ? everything is 64X64?
Your game is based on a 64x64 'block size' but not a 64x64 resolution. For example, on the menu screen the word 'start' is rotating and the edges of the surrounding box are smooth because the resolution is much higher than 64x64. Hope that makes sense. It's not a criticism of your game (which I like) it just doesn't meet the rules, viz: "The goal of the jam is to create a game with a resolution of 64x64 pixels or less"