The game made me think a lot.
Some combinations I found through trial and error. Although I tried countless times to create coffee but it wouldn't let m until I reach the end, please look into why that happen and try to fix it. Also best to look up the combinations on Google if you want to get the highest point. When it comes to the Nuke achievement best have Bomb + Mushroom ready to go. Regarding the 7 sins, I'd say you need Greed, Lust, Envy, Pride, Gluttony, Wrath, and Murder/Sloth/Theft/Heresy.
Lust = Sex + Sin (Sex = Man + Woman)
Gluttony = Food + Sin (Food = Man + Tree/Weapons + Beast)
Pride = Sin + Sin (Sin = Human + Apple)
Murder = Sin + Corpse (Corpse = Fire + Man/Human/ Demon + Human/ Human + Murder)
Wrath = Sin + Weapon (Weapon = Human + Metal. Metal = Stone + Fire. Stone = Lava + Water/Wind. Lava = Fire + Earth.)
Greed/Theft = Sin + Money (I find this easier than Lawyer + Money for it gives you Theft as well. Money = Copyright + Knowledge )
Sloth = Sin + Work (Work = Man + Money.)
Envy = Sin + Greed
Heresy = Sin + Religion (Religion = Prayer + Human. Prayer = Angle + Human. Angel = Light + Life. Life = Man + Woman.)
Good luck to you guys trying to collect some Medals. Anyway I suggest expanding the game more to allow for more groups and more combinations.