Can the Slice Media Player play H.265 (HEVC) Content
No, the hardware doesn’t support it. There are indications that with the CM3 upgrade, it can play it.
With CM3 you will be able to play up to 1080p24 H265 video… Even then there are occasions when you get skips in the video with high panning video
Of course you can always experiment with overclocking but only if you’ve got a suitable heat management system (my CM3 Slice has a copper slug that connects the processor to the case to help stop it overheating)