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!
Collect 1,000 Frozen Drops!
Wear Mr. Pinstripe's suit!
Warm George up!
Kill every monster!
Beat the game in less than an hour!
Get the Tommy Gun!
Find all three secret rooms!
Beat the game without getting hurt!
Sniff out all the clues!
Be a complete butt head.
Just be nice, OK?