14 games ranked by how much the tags Steam players vote on them overlap with ULTIMATE HARDBASS DEFENCE's. A rare tag counts for far more than one that sits on half the store, and popularity never moves a game up.
What they share most: Mature, Shooter, Memes, Female Protagonist, Zombies.

1·NEOMORPH
93% match · Mature, Shooter
76% of 696 reviews positive

2·HunieCam Studio
92% match · Mature, Memes
88% of 6,611 reviews positive

3·18+
92% match · Mature
69% of 851 reviews positive

4·Phantom Thief Celianna
91% match · Mature, Female Protagonist
63% of 328 reviews positive

5·Zombeer
90% match · Mature, Zombies
74% of 308 reviews positive

6·Country Girl Keiko
90% match · Mature, Memes
74% of 268 reviews positive

7·Onechanbara Z2: Chaos
89% match · Mature, Female Protagonist
79% of 1,075 reviews positive

8·Panty Party
89% match · Memes, Mature
91% of 1,165 reviews positive

9·Ruins Seeker
88% match · Mature, Female Protagonist
93% of 742 reviews positive

10·Niplheim's Hunter - Branded Azel
88% match · Mature, Female Protagonist
90% of 825 reviews positive

11·Princesses Never Lose!
87% match · Mature, Female Protagonist
81% of 428 reviews positive

12·DEAD OR SCHOOL
87% match · Mature, Female Protagonist
84% of 2,819 reviews positive

13·FATAL FRAME / PROJECT ZERO: Maiden of Black Water
87% match · Mature, Female Protagonist
83% of 6,557 reviews positive

14·Public Defense Corp
87% match · Female Protagonist, Mature
82% of 387 reviews positive
The closest matches to ULTIMATE HARDBASS DEFENCE on Steam are NEOMORPH, HunieCam Studio, 18+, Phantom Thief Celianna, Zombeer. They rank highest because their Steam community tags overlap most with ULTIMATE HARDBASS DEFENCE's, and shared tags include Mature, Shooter.
Every game is described by the tags Steam players vote on it. Rare, specific tags such as Mature, Shooter, Memes count far more than catch-all ones like "Indie" or "Singleplayer", and each game is scored on how closely its whole tag profile matches ULTIMATE HARDBASS DEFENCE's. Popularity never affects the ranking.