24 games ranked by how much the tags Steam players vote on them overlap with Band of Defenders'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: Real-Time, Real Time Tactics, Team-Based, Post-apocalyptic, Tower Defense, PvE.

1·Nuclear Dawn
83% match · Real-Time, Real Time Tactics
79% of 2,497 reviews positive

2·Element TD 2 - Tower Defense
80% match · Real Time Tactics, Tower Defense
90% of 3,235 reviews positive

3·AOD: Art Of Defense
79% match · Wargame, Real Time Tactics
79% of 391 reviews positive · 2 playing

4·Home Wars
79% match · Wargame, Real Time Tactics
79% of 1,189 reviews positive

5·Vectorio Classic
77% match · Tower Defense, Real Time Tactics
93% of 1,475 reviews positive

6·Stronghold Crusader HD (2012)
77% match · Real Time Tactics, Real-Time
97% of 21,124 reviews positive

7·Creeper World 4
77% match · Wargame, Real Time Tactics
95% of 4,734 reviews positive

8·Invasion Machine
77% match · Real Time Tactics, Wargame
65% of 632 reviews positive

9·Out of Ammo
76% match · Real Time Tactics, Tower Defense
84% of 736 reviews positive

10·Squad
76% match · Team-Based, Military
81% of 244,919 reviews positive · 4,990 playing

11·Arma Reforger
76% match · Real Time Tactics, Military
80% of 58,638 reviews positive

12·Attack on Toys
76% match · Real Time Tactics, Wargame
93% of 1,224 reviews positive

13·Artisan TD
75% match · Tower Defense, Real Time Tactics
87% of 2,533 reviews positive

14·War Planet Online: Global Conquest
75% match · Real Time Tactics, Wargame
62% of 982 reviews positive

15·Toy Shire
75% match · Wargame, Real Time Tactics
87% of 744 reviews positive

16·EDEN STAR
75% match · Base-Building, Tower Defense
52% of 1,120 reviews positive

17·Taur
75% match · Tower Defense, Base-Building
80% of 2,114 reviews positive

18·Syrian Warfare
75% match · Real Time Tactics, Wargame
87% of 5,602 reviews positive

19·Starship Troopers: Terran Command
75% match · Real-Time, Wargame
87% of 12,060 reviews positive

20·Foxhole
74% match · Wargame, Base-Building
79% of 53,211 reviews positive

21·Wargame: Airland Battle
74% match · Wargame, Real Time Tactics
87% of 4,457 reviews positive

22·Six Days in Fallujah
74% match · Wargame, Team-Based
79% of 16,522 reviews positive

23·Sanctum
74% match · Tower Defense, FPS
89% of 3,364 reviews positive

24·Call Of The Mighty Warriors
74% match · Tower Defense, Real Time Tactics
60% of 356 reviews positive
The closest matches to Band of Defenders on Steam are Nuclear Dawn, Element TD 2 - Tower Defense, AOD: Art Of Defense, Home Wars, Vectorio Classic. They rank highest because their Steam community tags overlap most with Band of Defenders's, and shared tags include Real-Time, Real Time Tactics, Team-Based.
Every game is described by the tags Steam players vote on it. Rare, specific tags such as Real-Time, Real Time Tactics, Team-Based count far more than catch-all ones like "Indie" or "Singleplayer", and each game is scored on how closely its whole tag profile matches Band of Defenders's. Popularity never affects the ranking.