The Simon toy was launched by Milton Bradley in 1978 with a big release party at the legendary Studio 54, which was then still in its first glamorous epoch under Steve Rubell. Simon had been developed by Ralph Baer, based on a badly done and therefore not very successful Atari arcade machine, Touch Me.
The concept of Simon is simple. The four color fields are buttons, and each represents a tone. Simon first plays a single tone, and the appropriate button lights up, which the player is now supposed to press. Then it repeats the tone and adds another one, and so on. The task of the player is to memorize and repeat this ever-growing tone sequence.
The name Simon, which was Milton Bradley's idea, Ralph Baer had
suggested Follow Me, is derived from the children's game Simon Says,
which seems to be popular all over the English-speaking world. In this
game, one kid gives instructions (usually to touch various body parts).
If these instructions are preceded with Simon says,
they are to
be followed, otherwise not. A player reacting the wrong way is out.
Usually the last one in gets to be it
and give instructions
in the next round.
Fernando Lagos' computer implementation was not the first one. There was at least one by Bob Lancaster, author of (among other things) Crux, under the name of Otra. Otra, which sported ASCII graphics, was not a faithful reproduction of the handheld toy. It featured a 3×3 playing field and slightly different gameplay. A more faithful version is found in the 1995 edutainment title Weird, where it is a minigame that on success opens a door. 1996 Kostas Symeonidis' Simon32 already had a non-rectangular window.
But I do think that this program was the first that so faithfully emulated the look of the original toy, yes, probably the first to go to such lengths to emulate the look of any object. Take for instance the power switch: it is not just a button graphic, you really have to push it to the right to exit the program. In this detail it clearly surpasses Tetris Jr. PC, where the controls of the original have no function and the real interface is a pop-up menu.
Fernando Lagos claims he tested it on every Mac available to him, and it ran on them all. I just gave it a short try on my Performa 630, where it ran very well (looked rather huge on the 640×480 desktop, however). It is possible that this was the first Mac game with an irregular window, though there were several on Windows at the time.
Meanwhile, Fernando Lagos had started the website elfoco.net and decided to use his game to promote it. The readme for the Windows version no longer gives his name and address, only the URL of the website, which is also displayed before the game starts. elfoco.net existed only fro a few years and was rather heavy on frames and JavaScript, and is thus preserved only rudimentary on the Wayback Machine, but it seems that Simon was Fernando Lagos' only downloadable program. The other products featured there were Java applets and graphics.
Simon for Windows requires the MFC42.DLL.