Zombie Defender: Epic Tower Defense

Zombie Defender: Epic Tower Defense is a strategic game focused on base defense mechanics. It has elements typical to the tower defense genre, where players must place and upgrade defenders strategically to fend off waves of zombies. It also adds its own twists, such as defenders having unique abilities and the option to use resources for base improvements. These details add layers of complexity to the gameplay and decision-making.

Here are some general thoughts and features that might make the game interesting:

Gameplay Mechanics:

1. Diverse Defenders: Offering a variety of defenders with unique abilities encourages players to experiment and find the best combinations.

2. Resource Management: Balancing between hiring new defenders, upgrading existing ones, and improving the base adds a resource management component to the game.

3. Environmental Traps: The inclusion of things like spikes and machine guns could add a fun layer to the strategy, especially if they can be activated or repositioned during play.

4. Combat Drones: These could serve as either a one-time use item for tough situations or as a permanent but expensive upgrade.

5. Tactical Layers: The game might include different kinds of zombies that require specific strategies or defenders to effectively counter.

6. Upgrades: Apart from defender stats, upgrades that impact the entire base or introduce new capabilities could add depth to the strategy.

User Interface:

1. Intuitive Controls: Given that it is playable on both desktop and mobile web browsers, the controls should be simple and intuitive. Left mouse button operation is a good choice for accessibility.

2. Visual and Audio Feedback: Good feedback mechanics can make the game more engaging. Knowing clearly when a defender makes a hit or when the base takes damage could be crucial.

3. Resource Displays: Clearly showing available resources like coins and oil can help players make informed decisions quickly.

Engagement and Retention:

1. Difficulty Levels: Introducing progressive difficulty can help to retain interest over time.

2. Leaderboards or Achievements: These could add a competitive element to the game, encouraging players to improve.

3. Daily/Weekly Challenges: Time-limited events could keep the game fresh and offer opportunities for bonus resources.

4. Multiplayer Mode: If feasible, a cooperative or competitive multiplayer mode could add a social element to the game.

All in all, "Zombie Defender: Epic Tower Defense" sounds like a well-thought-out game with a lot of potential for strategic depth and player engagement.