>Several decades ago, I do remember seeing a joke program titled something like "Realistic Spaceflight Simulator". The introduction states how this program shows you a "realistic depiction" of actual spaceflight to nearby Alpha Centauri using currently-available technology -- in real time. When you press a key to begin the voyage, the screen changes to a starfield and a running time elapsed display. Being that the program was written in interpretive BASIC, you could easily look at the program code. Perhaps not surprising there isn't much to the program -- and is obvious that user was never meant to actually finish the game. I did find it amusing that examination of the loop code between "start" end "arrived" display, revealed that the loop would take on the order of several tens of thousands of years to complete.

Should be updated for a 24 - 34 year time frame: https://en.wikipedia.org/wiki/Breakthrough_Starshot