What about Magicka (no DLC) for Cave Story+?
See also if there is something here you might want:
http://www.steamtrades.com/trade/VPuIJ/h-steam-keys-gifts-links-w-games-offered
I don't know if this thread is still good, but I have a copy of Frozen Synapse. As far as games I'm interested in, here are the ones I'm interested in:
Cave Story+
Gemini Rue
Papo & Yo
Little Inferno
Giana Sisters
Thief Gold
Stacking
Any trade along the lines of that (obviously not all of them for Frozen Synapse) sounds good to me. I'm putting the ball in your court as far as what offer because you probably have an idea of which games are valuable for you as trade chips, so whichever one(s) you want to get rid of most.
I have some of your wanted games: https://docs.google.com/spreadsheets/d/1RxhnwpEr528g-0pCVjrX3B5fjmLi3Kx4RPIrOH3NeX0/edit?usp=sharing
Have
orcs must die,
cave story+,
anomaly2,
blocks that matter,
draw a stickman epic,
gemini rue,
giana sisters twisted dreams,
little inferno,
papo and yo,
paranautical activity,
reus,
serious sam 3 bfe,
stacking,
to the moon,
tiny and big,
revenge of the titans,
thief gold,
puzzle bots,
galaxy on fire 2,
duke nukem megaton edition,
and yet it moves
Want
Half Life 2
Magicka (+DLC if you have it)
Trine 1/2
Frozen Synapse