I started Lumix Engine years ago for fun and as a test bed for new ideas, which were later implemented in my dayjob. Now I am using it to make a game. I never intended to fill some gap on the market.
What a fine question to ask on HN. Jesus, who cares, this is a one man project and it's amazing what he's done. And to top it off its released under the MIT license. If this doesn't impress you, I don't know what will.