Maybe I'm crazy. Maybe my brain is slowly turning into a gelatinous mush as those around me rightfully question my ever-more-precarious sanity. Or.... bear with me here... "Killing Floor 2" essentially holds all of the game design elements of a Tower Defense game, transforming itself into a shooter by turning the towers into guns and the defense points into the players themselves. Many of the key design similarities to common Tower Defense elements are as follows:
- Wave-based levels, where each wave becomes more difficult and there is a safe period of time between each wave to fix and bolster your defenses.
- Strategies are often heavily based around "lanes". Lanes can be temporarily blocked and trapped. (Welding.)
- The damage types and utility functions of towers are designed to counter - and be countered by - specific enemy types so that a variety is needed in order to survive the expected enemies. (Sirens, Scrakes, microwave damage, ballistic damage, etc.)
- Money is earned during a wave. It can then be used to buy more towers (guns), repair towers (buy ammo), etc.
- Towers are separated by tiers and cost levels. (Weapon Tiers.)
- Towers can be upgraded once bought/placed. (Upgrade system.)
- There is a "build limit", represented by a bar or number. (Weapon Weight.) Different towers use up different portions of the build limit. Players may not build more towers than the given build limit.
- Taking heavy damage (losing a player) or exhausting tower durability (ammo) can be costly for the following wave. Completing bonus objectives ("Defend the Area", etc) nets the player additional funds.