The absolute best bang for your buck on VR, without a doubt.
So how can it be improved? More officially supported modes and tools for modders. Just give this flower all the space it needs to grow. More modes, more players on a server, custom avatars, more weapons, better AI, maps with objectives and scripts and crap like that. A RC car bomb or flamethrower would be fun, or a harpoon gun. Capture the flag or just some kind of attack and defend base mode.

Anyway the game is worth it right now as is...