For side mission ranks, seems like all you need is to kill everything to get 3 stars. Take "Next Gen Radar" and make sure you get every red spot on the map before finishing it.
In "Glass of disguise" the green background keep's rotating clock wise. On the 2nd glass (where the shape colors match the ones on the door) go through the door that matches the symbol on the door with the green background... because green is "always right". That's what i thought then and it worked.
I was having fun with this game despite the typos, the "funny" crypt spinning effect and disappearing charges when their target dies, very slow fast mode... then the Valkyries showed up and I decided it isn't worth it.
 "Soccer Physics"){kind=icon}
 "Mechanical Commando 2"){kind=icon}
 "The Fancy Pants Adventures"){kind=icon}
 "Royal Offense"){kind=icon}
 "How Smart Are You?"){kind=icon}
 "Ninja and Blind Girl 2"){kind=icon}
 "Cursed Treasure 2"){kind=icon}
 "Defend your Honor!"){kind=icon}