Starlit Kart Racing (UP)

To get this achievement you need to complete the mission 100,000 Gems Collected!. To get to the missions on any menu press to check all your missions progress.

It only counts the Gems you collect in cups races and bosses battles. So when you pick your class to race with the 1x (150cc), 1.5x (300cc) and 3x (600cc)-*(unlocked with real money)* these DO NOT count towards that mission. But it does give you more Gems to spend on Skills.

However for an extra 25% of gems towards the mission you can use the BUNA BOSS KART as this skill is attached to this particular kart. But it will cost 960 GREEN TOKENS which you earn through playing the game or buy for real money, you can also buy the boss kart pack for real money.

As I was grinding out races for the other achievements I collected EVERY GEM in each cup (ALL 4 RACES). Some Gems are in crates, on the track or in a chest which you need to find the key on the track before you can open it. The keys and chests are all in plain sight.

To see which was the best cup to grind this achievement I wrote it down.
This was my list I wrote out with BUNA(+25%) and any other kart.

CUP. _______________________ ANY OTHER KART._________WITH BUNA(+25%)
PARALLEL PEAKS.___________ 1006 GEMS._______________ 1342 GEMS
SNOW MOUNTAINS.__________1234 GEMS.________________1646 GEMS
SUNNY FALLS.________________796 GEMS._________________1062 GEMS
GREEN WOODS._______________1191 GEMS._______________1588 GEMS
COG CASTLE._________________1141 GEMS.________________1521 GEMS
MIRAGE DESERT.______________1861 GEMS.________________2481 GEMS
LAVA CHAMBERS._____________1344 GEMS._______________1792 GEMS
SHADOW PIT.__________________1518 GEMS._______________2024 GEMS

So the best cup I found to grind is MIRAGE DESERT. All cups takes roughly the same time to complete, maybe at most a minutes difference either way.

THIS ACHIEVEMENT IS A GRIND BUT HOPE THIS HELPS.

the buna kart makes you win more gem +25 %