There are 4 Demo versions on MS-DOS: 8-bit, 24-bit, 3Dfx and 3Dfx Special. This Demo version is 8-bit on MS-DOS.
In general, there are few differences from the full version. Well, except for having only one city (Liberty City) and having a timer at the top of the screen when you're playing. It ticks and ticks for a reason. When you start a level, the countdown starts and the timer ends, at the end of 6 minutes the game process ends. But don't worry, 6 minutes is not forever, you can also restart the game. When you restart the game, the timer will again count down to 6 minutes.
You can start the game on the build DOSbox+Windows3.11, it will not work on normal DOSbox. An interesting fact: the 24-bit version can be run in a regular DOSbox, but in the "DOSbox+Windows3.11" assembly, the 24-bit version cannot be run.
Unzip the archive, transfer the folder with the game to the "DOSbox+Win3.11" build directory, preferably at {build directory}/C_Disk/{any place}. Run the assembly, and in Windows3.11 through the file manager open the folder with the game and run the game by clicking on "Demo8.exe".