Truthfully, although there are a few great Android games out there, the majority of the options for gamers in the Android Market are disappointing. One of the exceptions to this general rule is an incredibly addictive offering called Robo Defense.
This is a classic tower defense game with an objective to prevent the enemy from crossing the map and infiltrating your base. The enemy will always take the most direct route available. Your job is to build defensive towers of various types to blow the robot invaders to bits before they get to your base.
In this guide, we’ll take a look at some of the specifics of Robo Defense and also suggest some good Robo Defense strategies to help you win.
Robo Defense and Robo Defense FREE
There are two versions of Robo Defense available for download in the Android Market. The best idea is to try Robo Defense FREE first to get a feel for the game and see if you like it. The free version is limited to one basic map, where the enemies always enter from the left and try to get into your base on the right.
You’ll find that the reward points you earn can be spent on upgrades, accessible from the main menu. However, in the free version, these upgrades are limited. You can also select a difficulty level when you start a new game, and once again, this is limited in the free version.
Despite the limitation, Robo Defense FREE still offers a few hours of fun and it should be enough to persuade you to part with $2.99 for the full game.
Basic Controls for Robo Defense
The controls are simple and involve tapping the screen to select items and dragging to place them. You select towers from the icons at the bottom right of the screen, and drag them to where you want them by lifting your finger from the screen to build them on spot. You can simply drag your finger across the screen to scroll and tap on a tower to get upgrade options. You can also pause the action and fast forward using the controls in the bottom left. You can access the options and the main menu by pressing your Menu button.
Let’s take a closer look at the enemies and towers in the game before moving on to some strategies for winning at Robo Defense.
Robo Defense Enemies
One of the great things about Robo Defense is the wide variety of enemies. They can be divided into two categories – land based and air based. The land based troops will try to take the most direct route available, but you can block them with your towers and effectively force them to march through a maze. The air based enemies can fly straight over your towers so they need special consideration (we’ll take a look at this in the strategy section later).
Robo Defense Towers
There are three basic tower types available for you to build and they can be chosen via the three icons at the bottom right of the screen. Let’s take a closer look:
Machine Gun Towers
These are the cheapest towers in your arsenal and they fire continually at all types of enemy. They are only effective at close range. The basic machine gun tower costs $5 to build. You also have three upgrade options:
The basic Machine Gun Tower can be upgraded to a Medium Machine Gun Tower for $4 and then a Heavy Machine Gun Tower for $6. So the total cost for a Heavy Machine Gun Tower is $15. They’re good basic towers for attacking all kinds of enemies but they don’t do a great deal of damage.
You can also upgrade the basic Machine Gun Tower to an Anti-Air Cannon for $20 and then to a Heavy Anti-Air Cannon for $40. So the total cost is $65. The Anti-Air Cannons will only attack aircraft but they are much more effective against aircraft than the Machine Gun Tower is.
The final option is to upgrade the basic Machine Gun Tower to a Flame Tower. This will cost you $70. You can upgrade further to an Inferno Tower for $50. The total cost is $125. The flames are especially effective against infantry troops and they can set vehicles on fire so they’ll continue to do damage over time.
These towers cost $20 each and they fire rockets which will damage all enemy types, but they do have a reload time in between each volley. They have a good wide range. They also have three upgrade options:
The basic Rocket Tower can be upgraded to a Medium Rocket Tower for $30 and the rockets it fires will pack a heavier punch (x2). You can then upgrade to a Heavy Rocket Tower for $50 which will increase the damage dealt further (x3). So, the total cost of a Heavy Rocket Tower is $100. They will fire at all enemy types but are most effective against ground troops.
You can also upgrade the basic Rocket Tower to a Mortar for $50. The Mortar has a wider attack range but can only hit ground troops. You can upgrade it further to Artillery for $90 and it will have an even wider range and cause more damage. So the total cost of Artillery is $160.
The final option for the basic Rocket Tower is to upgrade to a Surface to Air Missile which costs $70. It has a slow reload rate and can only hit aircraft but it packs a real punch and has a very wide range. You can upgrade it further to an Advanced Surface to Air Missile for $90 and it will do even more damage. So the total cost for an Advanced Surface to Air Missile is $180.
These towers cost $10 each and they are absolutely vital if you want to win in Robo Defense; although, in basic form, they don’t actually do any damage. Instead, they slow your enemies down which gives the other towers longer to destroy them. They are effective with all types of enemy. Once again there are three upgrade options.
The basic Slow Tower can be upgraded to an Upgraded Slow Tower for $10 and then to an Advanced Slow Tower for another $10. The upgrades increase the slow down effect on any enemy hit but the tower does have a slow reload rate to begin with. The total cost for an Advanced Slow Tower is $30.
The Mine Tower option has to be unlocked via the main menu where you can choose to Spend Reward Points. The basic Unarmed Mine Tower will cost you $20 and to arm it you’ll need to spend a further $5. This powerful mine will deal out major damage, often killing multiple enemies. However, once it has gone off you’ll need to spend another $5 to rearm it. The total cost is $35 but then a further $5 every time you rearm.
The final option to upgrade the Slow Tower is the Teleport Tower, but you’ll need to earn 1 million reward points before you can unlock it. The basic Teleport Tower costs $20 but you’ll need to spend $3 to recharge it after each use. So the total cost is $33 plus an extra $3 for each subsequent use. The Teleport Tower will teleport any type of enemy that passes over it back to the start.
Upgrades and Reward Points
To begin with, it is better to get a good number of towers out to create a long path where the enemy is being constantly hit. Once you have the basic maze built you can focus on upgrading the towers.
As you advance it is essential to spend your reward points via the Spend Reward Points option in the main menu. You can increase your starting cash, increase your number of lives, and also improve the fire rate and damage dealt by each of the towers. A few special options, such as the Teleport Tower, are well worth saving up for.
Basic Map Strategy
There are various ways to approach the game, but your options become more limited when you get up to the higher levels. You want to build a maze structure using towers as walls and force the ground troops to weave as long a path as possible through your defenses so that they are being hit the maximum amount.
You need a mixture of towers for maximum efficiency. A valid starting strategy is to build a maze of vertical rows which forces the enemy to march up and down being hit again and again. You can use a pattern such as:
Machine Gun Tower – Rocket Tower – Slow Tower
Repeat this to create a maze and you’ll advance quickly. However, the flaw soon becomes apparent when you are hit by waves of fast moving aircraft which fly straight over your maze in the most direct route.
The Horizontal Maze
Because of the aircraft, you have to reserve the central horizontal row and the row above or below to deal with them. If you fill the central horizontal row with Slow Towers, build Rocket Towers on the row above, and upgrade them to Surface to Air Missiles as the game progresses, you’ll be able to deal with the large number of fast jet fighters that tends to pop up later in the game.
You can build a weaving up and down maze above and below this to send the ground troops on a long route round. The first few waves of each level are always ground troops, so start on the defenses to deal with them first. There are a few screenshots to illustrate this but much of the fun comes from creating your own mazes and patterns so you’ll want to experiment.
General Tips for Robo Defense
Looping sections with plenty of Slow Towers will get the most out of your firepower simply because your offensive towers will have more chances to hit the enemy.
In terms of tower types, the Rocket Towers are probably the most effective against the widest range of enemies, but until you upgrade the fire rate and damage, they won’t be good enough for higher levels. It is worth building Inferno Towers at the end of maze rows so that they have the maximum range of fire and can hit enemies all the way round the corner. If you have closed off areas, which are further away from the action, then fill them with Artillery because they have a greater range. Remember, there is a green zone when you click on a tower which illustrates the range.
The Surface to Air Missiles are much more effective than the Anti-Air Cannons but they have a long reload rate so it is vital you have a lot of fully upgraded Slow Towers if you intend to use them.
The start of each map is usually the toughest period because you have limited cash to spend. Focus your first reward points on increasing that starting cash.
If you buy the full game you’ll get access to a number of new maps and the gameplay is a great deal tougher. This is primarily because the maps have multiple entrances and exits, and on some of them, the enemies can pass horizontally and vertically. Waves of aircraft coming from the top down give you much less time to destroy them. You may want to start your defenses in the middle on these maps to avoid early disaster.
Robo Defense Exploits
There are a couple of game exploits you can take advantage of if you want to win at all costs. The AI is simple and it calculates the most direct route to exit. If you time it correctly, you can wait until an enemy passes near to the end of your defenses and sell a tower further back in the maze to create a new path. Now, quickly place a new tower to block the old path and the enemy will have trudge back through your maze. Just make sure you recreate the right structure before the next wave.
If you are determined to earn maximum reward points, you can also wait until the final wave has reached beyond the halfway point and begin selling your towers back at the start to increase your ending cash and therefore your bonus. Once again, this requires careful timing and you must make sure it really is the final wave.
Robo Defense is Addictive
There is no doubt that Robo Defense will get under your skin, and even the Basic Map is enough to entertain you for several hours if you get into the strategy options. It is well worth upgrading to the premium version for the extra goodies and the new maps will challenge you to come up with a whole new way of playing. In case you are wondering, there is no limit to the number of levels. Robo Defense will continue indefinitely so if you’re aiming to complete it you’ll be there forever!