Itd be nice to see some of the old micro-games from TheChunk's MinerWare added in. A lot of the current ones are missing the fun, fast and energetic appeal that the old minerware had. Also, introducing a gradual increase in speed would increase the fun factor (stolen from old MW :^) )
Addressing your ideas, they're all super cool and I'd love to see them and a few others implemented, especially the boss games - having only 3 to compete on gets repetitive.
Solid Thread, I can see a lot of thought has been put into this :)