Gemcraft

Gemcraft is a free-to-play Tower Defense series developed by Game in a Bottle and distributed by Armor Games, a major source of Web Games. It has a distinct Fantasy setting with a rudimentary storyline that varies between installments.

Currently, there are four installments:
 * Chapter One: The Forgotten
 * Chapter Zero: Gem of Eternity (April 16, 2009)
 * Lost Chapter: Labyrinth (February 17th, 2011)
 * Chapter Two: Chasing Shadows (Released on Armor Games April 4, 2014; rereleased on Steam April 30, 2015)

Generally, An Adventurer Is You, assuming that said adventurer is always a noble wizard out to reach some goal on the other side of the world, come hell or high water. In this case, come monsters, by the bucketload. You, the Squishy Wizard, must protect your tower (tower defense, get it?) at all costs, by placing towers next to, and traps on, the path leading to it. However, a key difference splits Gemcraft off from other tower defense games — instead of being able to upgrade your traps and towers directly, you must power them with gems. Gems are mostly obtained with a spell named Craft Gem (which is basically the source of the game's name), and have distinct colors (which affect the types of powers they possess) and levels (which affect their strength). By combining gems correctly, you can create better ones to better fight those evil monsters.

The Gemcraft Wiki has detailed information on the series; beware of spoilers.


 * All Your Powers Combined: Crafting multi-colored gems becomes less beneficial until you combine all 8 colors into one gem. At that point, it gains the power of all 8 gem types rather than the 3 dominant ones, and its damage, range, and firing speed all skyrocket. Averted in Labyrinth: Supergemming in this manner doesn't exist.
 * Damage Reduction: Armor level.
 * Dangerous Forbidden Technique: Labyrinth has a meta example: The glitch that allows the creation of near infinite strength gems has a chance of deleting your save file.
 * Chain Lightning: Lime gems can strike chain hits.
 * Disc One Nuke: One of the early stages in Gemcraft: Labryinth has a tower surrounded by eight amplifiers. Place a gem in each of the amplifiers, and the tower gem will kick ass. This nuke becomes MUCH more powerful if the player buys the "premium" version and uses endurance mode with this strategy to get a ridiculous multiplier to their XP gained.
 * Red gems in Labyrinth. They add a percentage of their kills to their damage. Meaning a red gem that's been there since the first wave can have a damage of over 1000 by the final waves and in fact out-damage gems of other colors several grades higher than it.
 * Freemium:
 * In Labyrinth, buying the Premium Version relaxes the difficulty curve and unlocks a handful of bonus levels.
 * In the Armor Games version of Chasing Shadows, buying the Magician's Pouch unlocks bonus levels, harder and more rewarding battle settings, and (most importantly) the ability to use the Chain Hit gem component on any field.
 * Mana: This is needed to build things, craft gems, cast spells, and performs double duty as hit points as well. It builds up slowly every second, but largely comes from monsters you kill, and gets increased by using orange gems in the right places.
 * Level Grinding: And lots of it. In Chapter Zero, you'll have to level up to 200 in order to max out all your stats, and in Labyrinth, there is no level cap for 3 of the skills. For the premium version, the Ritual skill will let you gain one starting and maximum mana for a set number of battle amulets you possess, based on its skill level.
 * Multi Mook Melee: Because it's tower defense.
 * Nice Job Breaking It, Hero: In Chapter 0, you spend the game searching for the Gem of Eternity. When you find it and capture it,
 * Player and Protagonist Integration: Type 2.
 * Skill Point Reset: You can do this for free at the skill screen.
 * Splash Damage: Red gems give splash damage in first two games. Lime gems give a multi-hit version (which is likely why red gems were changed.)
 * Sound of No Damage: The game plays a metallic clink if an attack on an enemy is nullified by Damage Reduction.