While my colleagues are working on mice that shine in all kinds of different colours, I went towards the old school.
For around 10 units of currency, you should be able to find the uDraw tablet for the PlayStation 3, the drawing tablet that brought down a company.
The device contains a large touchpad which can report one or two touches, for right-clicking (as long as the fingers aren't too close), a pen interface which will make the cheapest of the cheapest Wacom tablets feel like a professional tool from 30 years in the future, a 4-button joypad (plus Start/Select/PS) with the controls either side of the device, and an accelerometer to play Marble Madness with.
The driver landed in kernel 4.10. Note that it only supports the PlayStation 3 version of the tablet, as the Wii and XBox 360 versions require receivers that aren't part of the package. Here, a USB dongle should be provided.
Recommended for: point'n'click adventure games, set-top box menu navigation.
The second driver landed in kernel 4.12, and is a primer for more work to be done. This driver adds support for the Retrode 2's joypad adapters.
The Retrode is a USB console cartridge reader which makes Sega Mega Drive (aka Genesis) and Super Nintendo (aka Super Famicom) cartridges show up as files on a mass storage devices in your computer.
It also has 4 connectors for original joypads which the aforementioned driver now splits up and labels, so you know which is which, as well as making the mouse work out of the box. I'd still recommend picking up the newer optical model of that mouse, from Hyperkin. Moving a mouse with a ball in it is like weighing a mobile phone from that same era.
I will let you inspect the add-ons for the device, like support for additional Nintendo 64 pads and cartridges, and Game Boy/GB Color/GB Advance, and Sega Master System adapters.
Recommended for: cartridge-based retro games, obviously.
Integrated firmware updates, and better integration with Games is in the plans.
I'll leave you with this video, which shows how you could combine GNOME Games, a Retrode, this driver, a SNES mouse, and a cartridge of Mario Paint. Let's get creative :)