The single Crazy Machines 1.5 key activates two separate game libraries in your Steam account:
- Crazy Machines 1.5 Inventors Training Camp
Start with this game to sharpen your skills.
- Crazy Machines 1.5 New from the Lab
When the "Crazy Machines 2: Back to the Shop Add-On" DLC is added to the Crazy Machines 2 game library Steam omits the "In Library" indicator for this DLC in the Steam Store, but if your right click on the "Crazy Machines 2" entry in your Steam Game library and select "View Downloadable Content" the "Crazy Machines 2: Back to the Shop Add-On" entry is present and can therefore be played- this is an anomaly within Steam.