Streamlined games with straightforward controls & mechanics for short, casual playing sessions.
Casual traditional platform jumper games, where the player has to get through stages by jumping, running, gliding etc. while avoiding obstacles and/or enemies.
Example games: Subway Surfers, Super Mario Run, Jetpack Joyride
SHOOT/BEAT 'EM UP
Arcade style shooting and fighting games with simple controls and a LOT of action with no real emphasis on precise aiming or tactics/strategy.
Galaxy Attack: Alien Shooter
Example games: Archero, Galaxy Attack: Alien Shooter
Arcade games that don't really fit in any other Arcade sub-genre but are casual games with clear arcade nature and mechanics.
Example games: Bowmasters, Kick the Buddy
Means games that utilize tower defense mechanics in their core gameplay. In tower defense games, waves of enemies enter the screen from a certain point or side. The main goal of players is to prevent these enemies from reaching a certain point or line (usually the opposite side they're entering from) in the screen.
Plants vs. Zombies 2
Example games: Plants vs. Zombies, Chain Chronicle, Bloons TD 5
Classic board game -style titles, either straight up conversions to mobile or games that otherwise utilize board game mechanics.
Example games: Monopoly, Chess, Exploding Kittens