Sort of like an expansion pack to Windows 95, this adds additional features that enhance the Windows 95 experiences such as desktop themes, maintenance utilities and some bundled software like Internet Explorer which would be its debut.
Install
Looks like your typical Microsoft installer of the era
Post Install

The boot screen has changed!
Desktop Themes
A selection of themes from the Plus pack. Users of Windows 98 will find these themes look familiar as these themes later appeared in Windows 98 (Along with the Space and Underwater themes). These themes change everything, from the desktop icons to the toolbar layout and fonts (that carry over to the programs that you use), to the sounds and mouse cursor. Science and Inside Your Computer where my personal favourite, used to rock those a lot back in the day.
Utilities
DriveSpace: Compresses the entire dis to allow for more efficient use of hard disk space at the expensive of performance, only works on FAT16 volumes
Internet Starter Kit: Designed to help get users online
Task Scheduler / System Agent: Allows you to schedule certain tasks, such as programs being run at a specific time. Useful for maintenance tasks like Scandisk or the Disk Drefragmenter but also for anti virus programs. Also useful if you wish to run a program at a reoccurring time.
Visual Enhancements
These were designed for high performance systems of the time that supported graphics acceleration
High Colour Icons: By default Windows 95 only supports up to 256 colour icons, with the Plus! pack you can have icons with up to 65536 colours.
Window Dragging: The contents of the windows can be seen when the user drags the application window around the desktop. Previously only an outline of the window could be seen
Anti-Aliasing: Softens the edges of screen fonts and UI elements, similar to ClearType in Windows XP, using the hardware acceleration of the graphics card
Wallpaper Stretching/Scaling: Desktop wallpapers can be stretched to fill the screen if the image resolution does not match the display resolution, using the hardware acceleration of the graphics card
Product Catalogue

The multimedia catalogue, this isn’t installed onto the user system, instead its run straight off the CD-ROM. A showcase for other Microsoft consumer software and products.

Microsoft BOB, which was released from around that period.

Microsoft arguably made the most ergonomic mouses, and loved to show them off
Pinball

The Pinball game was originally developed by Maxis (Yes, the SimCity and The Sims Maxis) makes it debut here although the actual retail game had a lot more levels/machines, in plus pack only one level is featured.