Here is the full list of all 16 Baxters Venture: Directors Cut achievements.
Beat Act 1
Beat Act 2
Beat Act 3
Beat Act 4
Beat the game
Unlock all power ups
Get all gold doors in Act 1
Get all gold doors in Act 2
Get all gold doors in Act 3
Get all gold doors in Act 4
Get all gold doors in Act 5
Get all the gold doors in Challenge Levels
Unlock all Challenge Levels
Collect a total of 3000 chips