I went through all of the themes from Round 1 of theme voting; while most were astonishingly bad, some seemed like they could be viable.

Useless superpowers -1 - Basically "Inconvenient Superpowers."

Break the cycle +1 - I could see a wide variety of games being made from this; it provides quite a bit of freedom but isn't too vague.

Don't trust the game -1 - Leads to a lot of gimmicky games that give you inaccurate instructions, making gameplay difficult.

Absorb your enemies 0 - "Absorb" gives a wide variety of meanings; however, the theme restricts to games with focus on enemies.

No killing allowed -1 - Would probably end up with a lot of games that normally involve killing but that element is removed creating a huge hole in gameplay; otherwise provokes no ideas.

One item, many uses +1 - This theme could be very powerful.

You are the princess waiting to be rescued in the castle -1 - Pretty much all games would specifically have to be set with a princess in a castle.

Take one, leave one +1 - "One" can be a lot of things; however, it has to be taken or left. Not too broad or too narrow.

Scavenger -1 - Eh.

Control the environment, not the player 0 - This could cover a lot of ideas; people might abuse it and make a bunch of generic block-based puzzle games.

Indirect combat 0 - Kind of like "No Killing Allowed" but with a lot more possibilities and less terrible gameplay.

You're the final boss -1 - Yuck.

Permanent damage -1 - Too restrictive while being too vague; I have no ideas from this.

Automation +1 - This could be a lot of things.

Discovery (LD 19) -1 - Who the heck submitted a theme from a past Ludum Dare in the first place and how did it get to Theme Voting?

It only changes when you aren't looking -1 - Too restrictive while being too vague; I have no ideas from this.