I played games in the Tower Defense genre (because it’s the best genre obvs haha), and I was able to play Battle Cats and Kingdom Rush. Although they both fall in the Tower Defense genre, they have very different feels due to the theme.
Battle Cats is themed around cats with very cute drawings for units that give the game a very lighthearted feel. I really think that the art style makes it feel like a less serious game that invites players of all backgrounds since there are fewer barriers to new players in the theme itself. Cats as a theme invites players of all backgrounds, so the mechanics and difficulty of the game feel as though they must match. Players don’t have to think about where units are placed and simply need to worry about timing and pressing buttons that are lit up. Strategy is a little more complex with resource management and how players choose their upgrades, but this takes on lesser importance at least in the beginning of the game.
Kingdom Rush feels like a much more classic Tower Defense game with a medieval theme. This theme gives it a much more serious feeling that would attract much more “traditional” gamers. This in itself could be seen as a barrier to many players that may otherwise truly love a Tower Defense game. The mechanics also reflect this more serious theme as players must choose where to place their units and which ones to place in order to combat the enemies’ specific strengths and weaknesses. This game also has a resource management component that relies on players defeating a certain number of enemies in order to get enough resources to upgrade towers.