noun
overkill
Used for excessive force, effort, or response beyond what is necessary. Common in military, gaming, and everyday hyperbolic contexts.
その対策はオーバーキルだと思う。
I think that countermeasure is overkill.
このゲームではオーバーキルでボーナスが入る。
In this game, you get a bonus for overkill.
過剰 is a more formal, native Japanese term for 'excess' or 'surplus', while オーバーキル specifically implies excessive action or force that goes beyond what is needed to achieve a goal.
Borrowed from English 'overkill', originally a military term for nuclear destructive capacity exceeding what is needed to destroy a target, now used broadly for any excessive measure.