Update: a new post on this subject.
The V0.2.0 milestone has been reached!
As stated in the previous post the following additions have been made: start menu, in-game interactions (collection UI, timer/high-score UI), minimal special effects (object sounds, UI changes on object found), level ending (with high-score submit).
The game as of V0.2.0:

Some changes did not make it: the achievement system is still on the list but not that high on priority anymore.
The next official project update is scheduled at 18 March 2018, we will hit version 0.3 by then. It will go more in depth: more details, more levels, more content. And we will start the Beta by then and begin distributing it to the Beta testers through Steam.