• Concept Art 1 Location - Desperation Street - Cul-De-Sac - In your neighbours mailbox.
• Concept Art 2 Location - Desperation Street - Cul-De-Sac - Mailbox on the opposite side of the road to 1205
• Concept Art 3 Location - Desperation Street - The Orange Tree - Mailbox in front of 1121 Desperation St.
• Concept Art 4 Location - Anne-Claire's Room - The photo above the window.
• Concept Art 5 Location - Anne-Claire's Room - The bed side lamp
• Concept Art 6 Location - Hobo Alley - Cheswick & Grove - The wanted poser on Witch-B-Gone.
• Concept Art 7 Location - Hobo Alley - West Chesnut Park - Rubbish Pile (Behind three animate trash enemies from the dustman mission)
• Concept Art 8 Location - Hobo Alley - Grove Bend - Poster on the pub's window.
• Concept Art 9 Location - Hobo Alley - The Sh*thole - Picture next to the entrance.
• Concept Art 10 Location - Pelican Bay - Tollbooth - Ice cream sign just north of flying pricks darts mini-game.
• Concept Art 11 Location - Pelican Bay - Midway - Red Poster to the left of where the floor is striped red and black.
• Concept Art 12 Location - Pelican Bay - Permonade - The Heavy Anchor in the middle.
• Music Record 1 Location - Desperation Street - Cul-De-Sac - Unlocks When you first approach T.Kemper.
• Music Record 2 Location - Hobo Alley - The Sh*thole - Meat Grinder in the robot room.
• Music Record 3 Location - Anne-Claire's Room - Behind Anne-Claire on the shelf.
• Music Record 4 Location - Pelican Bay - Midway - Unlocks when you've solved the "Entertain Us" fortune (The second fortune in the Mistress Mysterious Case).
• Music Record 5 Location - Unlocks when you complete the game.

Self-explanatory. Just make sure you block as many of the attacks as you can to reduce the amount of damage you take during the fight.

How to kill Silent God without using HEALTH items.

Fill up your HOT TODDYs (8x320 damage), EXPLOSIVE CLOWN NOSEs (4x160 damage) and DYNAMITEs (2x1260 damage). You'll need one final ingredient; all 5 DOUBLE MILD WEAK SAUCEs to reduce his attacks to almost nothing.
You'll also need some (or all) of your Support Characters ready to keep the battle flowing. (This is not vital as they will charge-up during the battle.)

• Use up ALL of your explosive items. This will bring him down to around 38500HP.
• His first move is always INCREASE ATTACK, so use your first DMWS to reduce it. (He doesn't seem to ever do INCREASE ATTACK again for some reason.) Make sure you use the item AFTER he has done the INCREASE ATTACK, otherwise your DMWS will be canceled out.
• Attack with normal attacks, remembering to keep an eye on the PINK status icon above his strength bar and blocking any attacks he squeezes in. (Each attack will do around 600 damage.)
• (I tried using 3x Team-Up move, which does 3500+ damage to him, but you need to be good with your blocking as you'll be waiting ages between attacks.)
• When you see the PINK status icon disappear from his strength bar, just get one of your party to use another DMWS to decrease his attacks.
• At about 38000HP he falls to his waist and at 24000HP he's down to just his head! This is where the FUN begins. (You should still have over 300HP for every character. If not, don't worry. You can lose a character and still get the Achievement.)
• From 24000HP onwards, you need to be good with your BLOCK when he charges you. The timing is pretty precise; he will lift a tentacle, then just as you see it move down, hit a TRIGGER button to COUNTER-ATTACK. You'll probably be down to your last DMWS and once it goes, your timing is crucial. (You cannot COUNTER-ATTACK his other move, you can only block it.)
• Keep pummelling and COUNTER-ATTACKing away until he's finally defeated! (Give yourself a pat on the back!)

The real trick to this strategy is to try and keep the battle flowing as much as possible. If you're attacking him, he can't attack you! (The same applies to all enemies in the game.) So try to join the Support attacks with your Normal ones to minimise his opportunities.
It took me three attempts to get the Achievement and at the end Tycho still had 300+HP, the other two had 400+HP.