We present an ultra-compact system approach for snapshot, multispectral imaging. It is based on a slanted linear variable spectral filter mounted in close proximity to the entrance pupil of a micro-optical, multi-aperture imaging system. A compact demonstration setup with a size of only 60 × 60 × 28 mm3 is developed, which enables the acquisition of 66 spectral channels in a single shot and offers a linear spectral sampling of approximately six nanometers over an extended wavelength range of 450-850 nm. The spatial sampling of each channel covers up to 400 × 400 pixels. First, the concept, the optical design and the fabrication are detailed. After the optical performance characterization, a comprehensive calibration strategy is developed and applied. An experimental demonstration is performed by acquiring the spatial and the spectral information of an imaged test scene.