This probably would work best on a weapon itself, but it might work best as a combination between weapons and a specialized playertype, like the magician playertype using magic weapons.
Now onto the actual idea: charge attacks. Weapons with charge attacks would do two things: click once, the weapon attacks. If the mouse button is held down, you will begin "charging" your weapon. After a few seconds delay, you can release your mouse button and unleash a powerful attack. Potentially used through the "energy" bar.
Think of it like a spear sword combo, but unique per weapon.
Some weapon examples could be:
- wider swinging sword that fires a projectile on charge
- gun that shoots a more powerful bullet on charge. Bigger and more damage behind it
- rocket launcher that shoots a tank shell on charge
- bow that fires 10 arrows in a wide pattern on charge
- spear that can affect a long but narrow range in front of the player. Still throws the spear on charge
