Thanks so much for playing, I'm glad you enjoyed it!
Assuming you haven't started a new game, you can hit the "continue" button on the main screen to pick up from final boss level. The core good ending is achieved entirely in how you defeat Felicity's final form... finding evidence only slightly alters the ending.
My thinking with the evidence was that I personally enjoy jumping puzzles, but other players can find them frustrating. I decided I'd include them as non-essential bonuses. Getting even one piece of evidence is enough to (slightly)alter the ending, the rest is just personal achievement.