Here is the full list of all 24 Tunche: Arena achievements.
Defeat Boutu in Horde mode without being damaged.
Beat Horde mode without having spent XP on the Skill Tree.
Reach Wave 50 in Endless mode.
Get a total of 50 S, SS or SSS kills in Endless mode.
Reach SSS combo style.
Reach SS combo style.
Use all the skills.
Defeat 10 giant frogs in total.
Defeat 30 trunks in total.
Beat Horde mode without having chosen any reward.
Defeat 75 monkeys in total.
Defeat Boutu in Horde mode.
Defeat 50 peccaries in total.
Reach S combo style.
Defeat one enemy of each type.
Defeat 200 frogs in total.
Clear a Wave without getting hit.
Air juggle the frog plushie 5 times.
Annoy the Skill Tree guy
Access any of the Leaderboards.
Buy a skill in Endless mode.
Complete a Wave in Endless mode.
Choose a reward in Horde mode.