The three "unknown achievements" at the bottom are for finishing the game as a chef, range, or knights. You must satisfy all the requirements and click "restart" in the ending tab (this will also give a bonus to that run's earned multiplier). As of right now, you only have to do the building and payment once ever, but you must meet the stat requirement during that run (for ranger and knight).
Level 14: The gem on the top left only looks like it's blocked off. If there's a pencil laying over paper, your doodle can get on the paper to go under the pencil.
Mutant tangerines technically allow you to increase tangerines indefinitely for free, but ultimately aren't that great--heroic are worth 8K as much, 5-D worth (minimum) 250K times as much. It's much faster to spend tangerines on those and not worry about mutants.
Nice mood, but everything is so slow--not just the character, but there's no way to speed up or skip cutscenes. That first one was about a minute and almost made me stop playing.
Bug: When you feed a burger to a whale, the display "You have X burgers" at Burger Ping does not decrement. You can only force an update by making a new burger. Corollary feature request is that it'd be great if you could get a count of the number of burgers you have at the whale farm.
I'll add these today!