Today we look at handheld titles.

The Rub Rabbits

Sega were pretty experimental during the DS era, more so when Sonic Team were involved, so during the time where Sonic was finding it's late 00s audience following the Sonic 06 fallout, Sonic Team made a bizarre dating game for DS called Rub Rabbits, unlike most dating games, in Rub Rabbits you have to constantly flirt and save the girl you are dating by using your stylus in mini games, rubbing if you will, the actual Rub Rabbits are your wingmen, it's a bizarre game but unintentionally hilarious.
B-Tier Game

Bubble Ghost
The Gameboy was a surprisingly versatile console even during it's early brick shape era but very few games could be considered that hard, even Megaman feels easier, enter Bubble Ghost, a puzzle game where you blow a bubble through increasingly difficult mazes, it's legacy as a speedrun classic has kept it alive, long after the Gameboy and DS family had been retired.
B-Tier Game

Pokemon Red and Blue
You'd think this game would be an easy S-Tier but rose tinted lenses are pretty common among my age group but having stuck with Pokemon up until today, going back to play the original is really rough as red and blue is a glitch filled mess, stuff like the Missingno trick, the Mew trick, catching safari pokemon outside the park and positioning yourself in certain pixels to trigger completion without even leaving Pallet Town are just a few of the glitches you can trigger in the average playthrough, even the mechanics allow you to cheese the game with just one Pokemon.
Back then it was revolutionary but now it's unplayable.
D-Tier Game