Happiness is an important feature. This feature allows some Pokemon to evolve in Pokemon in Vortex.
While there is no way to track the exact happiness points of the Pokemon players are training, players can see hearts will start to appear in the Pokemon's information. Too see any Pokemon's information, players have to click it's name to open the Pokédex. Hearts will appear as a Pokemon's happiness level is raised. The happiness will rise displaying one of four hearts: 
- A Pokemon needs 73 points to gain a heart. The exception is the last heart, which only takes 35 points.
- For the 1st heart to apear a Pokemon needs 73 points. The second heart will require 146 points, 3rd heart will need 220 points, and 4th will need 255 points (max). Is is also worth while to note that the 4th heart is significantly easier to get than previous hearts.
- All Pokemon that need happiness hearts to evolve need 3 hearts (220 points). The exception is Sylveon, which needs 4 hearts (255 points). Sylveon is the final evolved form of Eevee.
- The maximum number of battles that could be needed for a heart is 73 battles.
- The minimum number of battles that could be needed for a heart is 37 battles.
- Since happiness points per battle is randomized (1 or 2), players would need somewhere between 37 to 73 battles in order to gain 1 heart for your Pokemon.
- Happiness is not reset when a Pokemon is traded.
Pokemon that evolve with Happiness
| Base Form | Required Happiness | Evolved Form |
 Golbat |
Level 3 Happiness |
 Crobat |
 Chansey |
Level 3 Happiness |
 Blissey |
 Eevee |
Level 3 Happiness |
 Umbreon |
Eevee |
Level 3 Happiness |
 Espeon |
Eevee |
Level 4 Happiness |
 Sylveon |
 Pichu |
Level 3 Happiness |
 Pikachu |
 Cleffa |
Level 3 Happiness |
 Clefairy |
 Igglybuff |
Level 3 Happiness |
 Jigglypuff |
 Togepi |
Level 3 Happiness |
 Togetic |
 Azurill |
Level 3 Happiness |
 Marill |
 Budew |
Level 3 Happiness |
 Roselia |
 Buneary |
Level 3 Happiness |
 Lopunny |
 Chingling |
Level 3 Happiness |
 Chimecho |
 Munchlax |
Level 3 Happiness |
 Snorlax |
 Riolu |
Level 3 Happiness |
 Lucario |
 Woobat |
Level 3 Happiness |
 Swoobat |
 Swadloon |
Level 3 Happiness |
 Leavanny |