Announcing: "Portalethium"


The CG Cookie Crew is proud to present our tower defense game, PORTALETHIUM! Gridlocked at the intersection of two worlds, you - the valiant forces of blue - must protect your portal against the evil forces of orange

To save your portal is to save your planet!


 One Game, Two Purposes

We built PORTALETHIUM to be played.


Please play it and enjoy it! It’s an endless-style game that we hope will supply you with hours of beat-your-high-score incentive.The Goal?  Simple. You’re on the defense. Prevent enemies from making it to your portal for as long as you possible can.How?  This part is simple in concept but tricky to perfect. 

You have an arsenal of 3 TURRETS to ward off your enemy:


Canon : As a base turret, this weapon fires a slow-but-steady round at short-range enemies. It may not seem like much, but it can save your bacon when you don’t have many credits to spend.


Gatling : This weapon has a bigger range than the canon and a higher rate of fire. But those enhancements come at a higher cost of your credits.


Missile Launcher : She’s the most expensive turret with the biggest range and firepower. But the catch is she only fires flying drones, not land enemies.  


3 different enemy types are constantly making a break for your portal:


Moto: These two-wheeled blue buggers are your fastest enemy. Yet they are also your weakest foe. You'll have to act quickly to take down them down, but you won't need much firepower to do so.


Tank: These green juggernauts are the slowest of the enemy hoard. But what they lack in speed they make up for in armor. You'll need plenty of time, cannons, and gatlings to ward off tanks.


Drone: What's that in the sky? It's a bird it's a plane it's a...cliché example! The purple drones are the only airborne enemy and thus can only be engaged by your missile launchers. It can be easy to forget to look in the sky but, for the love of your home planet, don't! Lest the drones quietly rob you of victory.

We also built PORTALETHIUM to teach.

We thought it would be really cool to build a fully playable game and then turn around and teach how to make it! The “Creating a Tower Defense Game” Learning Flow will teach you how to build your own game from the ground up.

  • Building assets with Blender : Game assets don’t grow on trees. Someone has to build them. Why not you?! In this 20-lesson course I will teach you all the ins-and-outs of modeling and texturing modular assets for exporting to Unity.
  • Level design in Unity : In this course, Jonathan Lampel gives a crash course in using your modular Blender assets to build a playable level inside Unity.
  • Game development with Unity : Finally, Jonathan Gonzalez takes all the ingredients of this tower defense recipe and turns it into a playable game!
All 3 courses are available in the "Creating a Tower Defense Game" Learning Flow. Check it out HERE!

All said and done, this has been a huge team effort to make Portalethium a fun, educational reality. We’re talking 1 fully-playable game, 1 Learning Flow, 3 courses, 56 video lessons. It’s a big experience and we're eager for you to be a part of it!

Please screen shot your high score and post it to our Facebook and/or Twitter with #portalethium

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  • Dennis Russell (faithandworks)

    Level 101

    I guess I can live with that.

  • Hassan Alzahrani (armada7ksa)

    Nice game, I have achieved level 54! ( did not understand the point of building basses?
    I suggest to add more types of enemies and before going to any level the enemy photo will appear to give the player an idea for his weapon strategy. Some weapon can attack only some kind of enemy like the (Missile Launcher).
    One bug, as I played full game and the enemy did not go for the below attacking line at all?
    Great post and keep it up. Learning journey let us start :).

  • crew
    Kent Trammell (theluthier)

    Woah! New high score AFAIK!

  • crew
    Kent Trammell (theluthier)

    By bases, do you mean the 5000-credit obstacles? The intent was so they could divert your path of enemies with which your turrets could have more time to defend, thus improving your chances for higher levels. The enemies always choose the shortest distance to the portal which is why it doesn't choose the lower path unless you force it via obstacles.

    Thanks for the suggestions! We'd like to improve/iterate upon the game and release and updated version hopefully sooner than later.

  • crew
    Kent Trammell (theluthier)

    Thanks for playing, arnolds! The next 2 courses and final Flow all land next week :)

  • Addyson H. (addysonh)

    That's a pretty cool game! I played it about 3 times and only made it to level 6. ? I started learning about game assets, took a break because I took part in a competition and now that it's done I can get back to it. That means I get to continue figuring out how to paint my rock. ?

  • crew
    Kent Trammell (theluthier)

    Haha yes, you know how the saying goes: "Gotta learn to paint rocks before sci-fi modular assets" :D

    If game assets is your thing, there's a lot for you here:

  • Addyson H. (addysonh)

    Thanks! I checked out the video and it looks pretty interesting. I guess I'll see what happens. ?

  • cmalex79

    Is it me or is there a bug with some of the turret positions? You can emplace a turret, it will have a perfectly clear line-of-sight, and it'll just sit there tracking enemies without firing a shot.

  • megamidas

    Great game.. Quite enjoyable. Got to level 67. However, beyond level 52 the game starts to glitch a little. Some enemy units get stuck in a loop around certain corners (while they remain 'invincible'), thereby engaging the turrets and 'blind' to other units that are not affected by the glitch. Deleting turrets and replanting them seems to help momentarily until the next batch of units hang again.

    Bikes are the biggest culprits as they sometimes become 'invincible' regardless of how many turrets are shooting at them. So one or two will glitch while the rest remain vulnerable to the turrets firing. Of course, these 'Rambo' bikes will go on an occupy your base ):

    Otherwise, great simple concept that I look forward to learn how you guys produced it.

  • crew
    Kent Trammell (theluthier)

    Indeed, I've run into that bug as well.

  • crew
    Kent Trammell (theluthier)

    Thanks for this feedback. I too have seen enemies get hung up at corners occasionally, though I can't say I've seen them become invincible. But we'll consider the bug and plan to update the game in the near future!

    Btw the whole flow is no available if you're still interested in seeing how the game is built!

  • Leonardi Caraballo (leonardi)

    this is nice, I'm on level 54 ;)
    now is time to learn how to create it!
    this is a great idea, create a tutorial and a final product at the same time! love it!

    *hope to see one in Unreal Engine :(

  • Mike Mortensen (zhakalendk)

    The overall game is a good idea and I can't wait to take the course. However, I experience a variety of bugs.
    1. Placements for turrets is set up in a weird way. The designer here didn't think of turret range, line of sights or cross path shooting.
    2. Turrets can't be removed or replaced.
    3. The Anti Air canon's first shot always miss the target unless the enemy is right above it.
    4. The turrets (Besides anti air canon ) can't shoot at close range. Which means that the turret spot next to the portal will not fire when enemies are passing it.
    5. Half the map is not utilized.
    6. Too many turret spots block the turrets from shooting.

    Also.. I don't know why. I've looked trough the comments here and see people have the ability to replace or remove turrets and also have an extra building. The base.
    Does features definitely does not exist in the version that shows up in my browser.

  • crew
    Jonathan Gonzalez (jgonzalez)

    zhakalendk I'll address your questions.

    1. This design is how just about every Tower Defense game operates. Some utilize slightly different techniques but overall it's up to the player to determine what the best line of sight will be for the turrets they utilize. You can line them up in a row, or place them out sporadically where you see fit. I personally would prefer less places to put down turrets, but in the end we decided to opt for all flat areas to be a place for turrets to be used.

    2. Turrets in the base game are not meant to be removed or replaced. I did make modifications to the build of the game that allowed this, but the game taught in the course does not go over this.

    3, The missile missing the first shot was an early bug and was fixed. It was due to how the targeting system was acquiring a target first before firing rather than keeping track of the moving target. So the missile ended up flying to an area that the enemy was no longer at.

    4. I haven't experienced the turrets not firing at close range but this may be due to turret placement and how close an object is to the turrets.

    5. The map being utilized is up to how you place turrets down. The enemy will try the closest path to get to the destination. If you block that path then it'll find another way around. The base game doesn't utilize any complex AI for navigation so we let players determine the path. Initially the game was much harder but we found it wasn't as enjoyable when the enemy was too smart.

    6. Too many turrets is a fault of the player. We let the player decide where to place turrets, if you place 4 in a group together then it's bad tactics by the player. The turrets won't shoot other turrets. Initially we decided between having turrets block each other or having them shoot through each other. We went with the former as it ensures that the player properly utilizes the space given to fire at the enemies.

    I did make updates to the game soon after publishing, which included an optional "obstacle" tower that blocked a path completely. It also included the ability to "recycle" turrets and get money back. I'll have to see if we still have that version available, if so I'll update the blog post to include the new version.

    Overall though this is a chance for you to see the inner workings of how this game was built. Any changes you'd like to see made you can create them yourself. There's a ton of variation you can include with a TD game and this project is a stepping stone towards building that.

  • Adrian Bellworthy (adrian2301)

    Great game!! Been playing for hours. got to level 58!!! What's the highest score?

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