Here is the full list of all 12 Pinstripe achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Catch 13 butterflies!
Be a complete butt head.
Wear Mr. Pinstripe's suit!
Warm George up!
Find all three secret rooms!
Collect 1,000 Frozen Drops!
Get the Tommy Gun!
Beat the game without getting hurt!
Beat the game in less than an hour!
Just be nice, OK?
Sniff out all the clues!
Kill every monster!