Here is the full list of all 14 Old Tunnel achievements.
Get the maximum rank
Buy all types of weapons
Buy all the goods in the store
Buy an egg
Run 100 meters
Run 500 meters
Run 1000 meters
Run 2500 meters
Destroy the level 1 boss
Destroy the level 2 boss
Destroy the level 3 boss
Destroy the level 4 boss
Complete the game
Run 300 meters