I understand the hate Sonic Lost World gets, but I feel it is mainly directed at it because it is the followup to Generations and because it does too many Nintendo-y Mario-esque things when it really should be trying to be a SEGA-y Sonic-esque game. Still, given it is not actually the followup, from a development standpoint, to Generations and it was released as a Wii U exclusive and thus aimed more for the Mario crowd it really isn't as bad as some say.
It is incredibly solid in terms of how polished it feels. Nothing really felt off or broken like, say, Sonic '06 or Sonic Adventure were (the former had no excuse, the latter did seeing as it was a launch title and an early high speeds platformer for that generation).
Story was weak and childish, but then again this is a kid-friendly franchise on a kid-friendly platform. I thought the art direction and music was top notch!
In terms of what they have planned for 2016 (and trust me, they DO have something planned), I feel as though it will be as polished as Generations or Lost World was. Likely more than Generations given the amount of time they have had. I am very optimistic.