Alpha is a period of development of Scrap Mechanic. It began in October 2014 and ended on January 20th, 2016, when the game entered Beta and was released on Steam.
Alpha had many differences from Beta. Below are the differences that can be identified from official posts, videos, and images.
This page is a work in progress. Images coming soon.
Blocks
Concrete Block
A solid grey block appears as early as the debut trailer, which appears to be an early version of Concrete.
Stone Block
A darker grey block with a texture is seen a few times, presumably Stone. A Stone block is mentioned once.
Colored Blocks
Various colored blocks are seen in a few early images. Blue, cyan, and yellow are some of the colors seen.
Tools
Paint Tool
There is evidence of a functional Paint Tool in many screenshots, most notably in Devblog 5. Various parts and blocks have obviously been recolored.
Connection Tool
The Connection Tool was originally named the "Connect Tool". It also had a transparent screen, according to a model render.
Handbook
The Handbook had less tabs, a very different HUD icon, and didn't have a viewmodel.
Machine Parts
Driver's Seat
The Driver's Seat had a fuel bar on its screen up until the very end of Alpha. It may return in Survival Mode.
Engines
The Gas Engine and Electric Engine had a different GUI, resembling the top of their models.
Bearing
Bearings had a solid orange color in early Alpha.
Controller
The Controller had a reverse mode, indicated by double edged arrow icon next to the loop icon in the GUI. Presumably, when the sequence was completed, it would perform the sequence in reverse, then start the sequence again.
Switch
Switches weren't animated and its lights didn't glow.
Items
All items had smaller, perspective-distorted icons.
Parts
Chair
A chair was briefly seen in the debut trailer.
Miscellaneous
The 4-way arrow icon seen when a block is selected was yellow.
A hammer was shown when placing an object on a Bearing.
The connection lines were once dotted.
In early Alpha, the crowbar was not shown when removing an object.