Rushing in Impossible Creatures is a tactic that involves mounting an early attack against an opponent, usually with the intention of putting them out of the game altogether.
It is most often used in 1v1 battles to achieve a swift victory, but is less effective in combat when the player has more than one opponent. This is because rushing in the early game requires a lot of resources to have a chance of success.
Rushing works best on small maps that have fixed starting positions, as you know exactly where your enemy's base is. If you want to start attacking right away, be sure to have a creature in your army that costs very little or no electricity. Create more Henchmen while you begin setting up for the rush, as they should provide enough coal for you to continually produce creatures and keep the pressure on your opponent. When you mount your attack, your biggest priorities should be the enemy Henchmen, even if a Soundbeam Tower or two is attacking your creatures; if you go for the tower(s) first, the enemy can simply repair or replace it. Distracting or killing the Henchmen also harms your enemy's economy and therefore reduces their ability to fight off your attack.
The "Chamber rush" is a tactic that involves building a Creature Chamber close to your enemy's base as soon as possible. It follows the same general strategy as other rushes, but can be more useful for maintaining a continuous attack on the opponent.
"Henchmen rushes", as the name suggests, comprise an attack force made entirely of Henchmen. This is generally less likely to succeed, but can be amusing for you and humiliating for your opponent. Micromanagement is crucial when employing this type of Rush, such as taking injured units away from the battle. Keep in mind that enemy Henchmen recieve an attack bonus against yours when near their Lab.
If your rush is successful, your enemy should not be able to mount any more defenses after being overwhelmed by your creatures, and your forces are strong enough to kill Henchmen as fast than they can produce them. If your rush attack fails, the chances are that you have still disrupted their setting up and they have been stalled more than you have, which at least gives you an early advantage in the game.
Because most creatures in the early game are weak, Soundbeam Towers will be an effective line of defense but are fairly expensive. Surrounding your Towers with Bramble Fences allows you to shield them for a very low cost, and most low-level creatures will have difficulty breaking through the Fence and recieve damage in the attempt.
Bramble Fences can also stop Chamber rushes altogether; if the enemy starts building a Creature Chamber near your base, you can attempt to kill the Henchmen before they complete it. If, however, you do not think you can stop them in time, surround the Chamber with Bramble Fence. This will prevent it from spawning any creatures and causes your enemy to have wasted time and resources in the process.
Henchmen rushes are generally easier to fight off because of the attack bonus given to your own Henchmen when near their Lab. If you would prefer to use creatures to defend your base, be aware that ranged and artillery attacks deal greatly reduced damage to Henchmen but melee inficts its full attacking power.
Lab rushing is a specialised tactic that involves mounting an all-out attack on the enemy's Lab. Unlike other rushes, this almost never appears early in the game as it is often carried out by flying units. Flyers are ideal for Lab rushing because they can "overlap"; that is, many flying units can occupy a small space and will not get in each other's way.
Most creatures intended for this tactic will have high melee damage and/or Barrier Destroy, because the Lab as a structure has a lot of hit points. They can be designed with little regard to their own hit points and defense as this will make them cheaper, allowing a player to build a large number of Lab Rushers units quickly. Because this should be executed as a sneak attack, other useful traits for your creatures would be high speed, Camouflage or Digging if they are non-flyers.
The best time to carry out a Lab Rush is while a battle is happening elsewhere. This is because a portion of your target's creatures, or all of them with some luck, will not be present to defend the Lab you are about to attack and the enemy's attention may be diverted away from their base. Another useful point is to avoid taking a direct route to the target; mounting the rush from an unexpected direction gives them less time to react and therefore increases your chance for success.
With the above points in mind, defending against a Lab Rush requires close attention and fast reactions. Your greatest weapon against this kind of attack is Lab Defense, which will make the Lab invulnerable, but a player must remember that it will cost a lot of electricity even if kept on for a short time. To actually vanquish the Lab Rushing force, Anti-Air Towers in large enough numbers should make short work of them because, as previously noted, they are often very weak defensively. Soundbeam Towers serve the same purpose against ground creatures, and in both cases upgrading your Towers can mean the difference between survival and defeat.