Being a robot isn't always fun. Whereas other robots get to chase after pets and use grappling hooks to navigate flashy environments, Cargo-Bot is stuck picking up and putting down colored crates in a nondescript warehouse. Ah, well. Such is the life of a robot.
As a neat little puzzle game by Two Lives Left, Cargo-Bot's premise is simple: program a robotic crane to rearrange crates so they match the layout at the top of the screen. The method by which you do so is similar to our old favorite Light-Bot 2.0: drag and drop instructions on and off the four command bars on the left until you've got something good, then hit the play button at the bottom to see how she runs. The fewer instructions your program uses, the better your star ranking will be if it works. Suffice it to say that you'll have to worry about a handful of subroutines, conditional instructions (e.g. only move the crane left if it's holding a yellow crate), stacks of recursive calls, and many clever combinations of the above throughout the game's 36 levels.
The clever and brainteasing puzzles, adorably minimalistic soundtrack, and clear yet non-distracting graphics are more than worth the price of admission alone (it'd have to be, the app is free), but what really makes Cargo-Bot special is that it's the first game to hit the App Store that bears the distinction of having been created entirely on an iPad, using Codea. Codea is another iPad app from Two Lives Left, a programming utility designed for creating games and simulations. The gameplay, music, the cool physics effects when the crane crashes into a wall—it was all done on Codea.
Cargo-Bot is a first, and it's a really good first. If you've got an iPad, grabbing this game will be the best decision you made since you started to read this review!
NOTE: This game was played and reviewed on an iPad. Game was available in the North American market at the time of publication, but may not be available in other territories. Please see individual app market pages for purchasing info.
Walkthrough Guide
(Please allow page to fully load for spoiler tags to be functional.)
Cargo-Bot Walkthrough
General Info
Each time you start a new level, take a moment to examine the initial placement and goal position of the crates and look for simple, repeatable patterns.
The title of the level itself usually contains a clue or a hint towards the solution.
Then try to devise a solution to just get the job done, not worrying initially about how many registers you're using. Once you have a solution, and if it's less than 3 stars, then start to work on optimizing it.
This game rewards stars for completing the goal with a minimum number of registers (instructions), therefore some 3-star solutions may not be the most elegant solution possible. Part of the enjoyment of this game may come from devising a solution that doesn't get 3-stars but gets the job done in an elegant or efficient manner.
While mastering the art of the function call (Prog 1, Prog 2, etc) is an obvious skill this game requires, a not-so-obvious skill you must master to get far in this game is that of the programming stack. See the Advanced Technique spoiler for an example of using the stack.
Advanced Technique: The Programming Stack
The stack is an invisible structure that stores unexecuted instructions in a manner that may not be very obvious. Every time you call a function, all of that function's instructions get placed on the stack.
By calling a function recursively (calling Prog 2 from within Prog 2, for example), instructions of that function that follow the recursive call remain on the stack (the stack is "wound" up) and are executed in the event the recursion ends (thus the stack "unwinds").
Understanding and exploiting recursion and the stack will be necessary to solve some of the more difficult levels.
The following example is meant to show you the behavior of the stack, and it uses the Easy level, "Double Flip". Try the example yourself to see the results as you follow along with the description.
Suppose you have a pile of 4 crates that you want to move one position to the right. (Screenshot)
A player unaware of the stack might come up with the solution in the screenshot. This particular program first goes down and fetches a crate and then calls Prog 2.
Prog 2 has 6 instructions that are placed on the stack:
move to the right
put the crate down
move to the left
go down and fetch another crate (if one is there)
call Prog 2 (if holding a crate) to do it all over again
AND move to the right
Recursion in Prog 2 will begin to unwind when there are no more crates left to pick up: The call to Prog 2 will fail, and then the "move to the right" call will get called 4 times in succession, one for each time Prog 2 was called, thus causing the claw to run into the right barrier and break.
This unwinding of the stack occurs because the 4 unused "move to the right" instructions must get executed before any other instructions can be called.
For a more exaggerated display of the stack's behavior, try putting a "move the the left" following the "move to the right" instruction at the end of Prog 2, and then run the program again.
Level Solutions
Tutorials
Cargo 101 (3 stars, 3 registers)
Transporter (3 stars, 5 registers)
Re-Curses (3 stars, 5 registers)
Inverter (3 stars, 10 registers)
From Beneath (3 stars, 6 registers)
Go Left (3 stars, 9 registers)
Easy
Double Flip (3 stars, 6 registers)
Go Left 2 (3 stars, 4 registers)
Shuffle Sort (3 stars, 9 registers)
Go the Distance (3 stars, 5 registers)
Color Sort (3 stars, 10 registers)
Walking Piles
Walking Piles (2 stars, 13 registers)
Walking Piles (3 stars, 10 registers)
Medium
Repeat Inverter (3 stars, 7 registers)
Double Sort
Double Sort (3 stars, 14 registers)
Double Sort (3 stars, 11 registers)
Mirror (3 stars, 7 registers)
Lay it out (3 stars, 7 registers)
The Stacker
The Stacker (3 stars, 10 registers)
The Stacker (3 stars, 8 registers)
Clarity
Clarity (2 stars, 9 registers)
Clarity (3 stars, 7 registers)
Hard
Come Together (3 stars, 7 registers)
Come Together 2 (3 stars, 8 registers)
Up The Greens (3 stars, 8 registers)
Fill The Blanks (3 stars, 12 registers)
Count The Blues (3 stars, 11 registers)
Multi Sort (3 stars, 11 registers)
Crazy
Divide by two (3 stars, 13 registers)
The Merger (3 stars, 7 registers)
Even the Odds
Even the Odds (2 stars, 13 registers)
Even the Odds (2 stars, 12 registers)
Even the Odds (3 stars, 10 registers)
Genetic Code
Genetic Code (3 stars, 18 registers)
Genetic Code (3 stars, 16 registers)
Multi Sort 2 (3 stars, 17 registers)
The Swap (3 stars, 7 registers)
Impossible
Restoring Order (3 stars, 17 registers)
Changing Places (coming soon)
Palette Swap (coming soon)
Mirror 2 (coming soon)
Changing Places 2 (coming soon)
Vertical Sort (coming soon)
Bonus Levels
Coming soon!
Shortest Known Solutions
Coming Soon!
If you have a shorter solution than one posted here, please post a screenshot of the formula and we'll add it here.
Tutorials
Cargo 101
Transporter
Re-Curses
Inverter
From Beneath
Go Left
Easy
Double Flip
Go Left 2
Shuffle Sort
Go the Distance
Color Sort
Walking Piles
Medium
Repeat Inverter
Double Sort
Mirror
Lay it out
The Stacker
Clarity
Hard
Come Together
Come Together 2
Up The Greens
Fill The Blanks
Count The Blues
Multi Sort
Crazy
Divide by two
The Merger
Even the Odds
Genetic Code
Multi Sort 2
The Swap
Impossible
Restoring Order
Changing Places
Palette Swap
Mirror 2
Changing Places 2
Vertical Sort
Bonus Levels
Coming soon!
This is still a work in progress, filling in the blanks as quickly as I can. Contributions welcome! :)
This quickly became one of my all-time favorite games. I hope we get a level-editor added to it soon.
Posted by: Jay
|
May 7, 2012 4:36 PM