Epitaxially grown RuO2 films on TiO2 (110) exhibit significant in-plane strain anisotropy, with a compressive strain of -4.7% along the [001] crystalline direction and a tensile strain of +2.3% along [11¯0]. As the film thickness increases, anisotropic strain relaxation is expected. By fabricating Hall bar devices with current channels along two in-plane directions, (001) and (11¯0), we reveal anisotropic in-plane transport in RuO2/TiO2 (110) films grown via the solid-source metal-organic molecular beam epitaxy approach. For film thicknesses (tfilm)≤3.6 nm, the resistivity along (001) exceeds that along the (11¯0) direction at all temperatures. With further decrease in film thickness, we uncover a transition from metallic to insulating behavior at tfilm≤2.1 nm. Our combined temperature- and magnetic field-dependent electrical transport measurements reveal that this transition from metallic to insulating behavior is driven by electron-electron interactions.