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The True Slime King is a single player hardcore puzzle platformer with a focus on tight controls, challenging maneuvers, and mind-bending puzzles. All of this is achieved with just three buttons: left, right, and jump. Use your sliminess to stick to walls and cling to ceilings in order to avoid obstacles and reach hidden items. Whether you're a speed demon crushing records or you're just interested in progress through the story mode, one thing is guaranteed: you will die a lot in the process. But don't worry, you'll be respawned and back in the action just as fast as you can die.

Check out more about the game on the official Slime King YouTube Channel:

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This update brings full controller support to the game. In addition, the options keybindings area and the level editor has had a major overhauls.

options menu

level editor

Changes and Additions:

  • Added full controller support Quick Play and Level Editor can now be navigated with controller and keyboard. Quick Play and Level Editor used to only be navigable by mouse.
    • For the Level Editor, this included building an in-game file browser. This comes with the benefit of allowing the game to stay in full screen mode when browsing for files to load/save levels.
  • Level Editor revamp:
    • All settings (including undo/redo history) are now saved between editing and playtesting, allowing you to playtest a level and quickly resume editing from where you left off.
    • Added more tools on the topbar.
      • The rotate tools allow you to rotate objects to their different variations instead of needing to select the specific rotation on the sidebar. This saves time and declutters the sidebar.
      • Select tool to Level Editor - Allows for multiple objects/tiles to be selected, moved, and deleted.
    • Reworked how playtesting is done to massively decrease the lag time it took to load the level up for playtesting.
    • Pause menu can now be brought up when playtesting.
    • Buddy blocks now have arrow indicators.
  • Reworked the on-screen keyboard popup for entering text into the profile create area. The keyboard popup also now shows up for the quick play text fields.
  • When resizing a level in the Level Editor, instances outside of death boundary are now removed.
  • Removed objects in the overworld above the following levels to make the level number text be on the background tiles instead of overlapping objects.
    • lvl_1_14
    • lvl_2_1
    • lvl_2_20
    • lvl_4_5
    • lvl_4_9
    • lvl_4_17
    • lvl_4_19
    • lvl_5_1
    • lvl_5_2
    • lvl_5_5
    • lvl_5_12
    • lvl_5_15
    • lvl_5_20
  • Changed walls/thorns in the overworld to move faucents to be closer to the following doors:
    • lvl_3_16
    • lvl_4_1
    • lvl_4_3
    • lvl_4_5
    • lvl_4_11
    • lvl_4_14
    • lvl_4_19
    • lvl_5_1
    • lvl_5_2
    • lvl_5_3
  • Moved faucets 16 pixels farther away from many of the doors (either by moving the door or the faucet) in the Echoing Entrance and Crystal Caves. This was done to make it harder to accidentally enter the faucet when trying to enter the door.
  • Made overworld easier in the following places:
    • Route from Metal mines blue zone to orange zone.
    • Route to lvl_4_12.
  • Added purple crystals on the right side of the flip flop block near lvl_5_16 to prevent players from going up and to the right when the flip flop block is in the horizontal state.
  • Added controller rumble when player loses a heart.
  • Added shortcut in Echoing Entrance from the blue subzone to the portal area so that the portal can be reached before the end of the Echoing Entrance.
    Changelog v1.7.0 - Full Controller Support

  • Rumble is no longer a toggle option; it is a slider option, so players can set how much rumble they want to have.
  • Changed default fastest replay alpha from 0.5 to 0.4.
  • Changed default replay alpha from 0.3 to 0.2.
  • Changed default death alpha from 0.2 to 0.15.
  • Reworked the area near the Secret Shadowsphere portal in the overworld to make the portal accessible from the start of the Secret Shadowsphere.
  • Sorted objects and tiles in the overworld gamemaker room save file to make the overworld load slightly faster (by allowing it to load all instances of a specific asset before moving on to the next asset).

Level design changes:

  • Fixed a very easy skip in lvl_2_20

Bug fixes:

  • Fixed issue with replays not saving (this issue was introduced in v1.5.1).
  • Fixed issue with not being able to delete replays/deaths in Quick Play.
  • Slime king's dust in the tutorial area was green, but is now white.
  • Fixed issue with the button sound being played multiple times on the name create popup when holding the enter button to creating a new profile.
  • Fixed issue with interactable glow setting not affect faucet glow.
  • Fixed issue with song positions not resetting between profiles.
  • Removed pause menu options for deleting replays and deaths in any areas of Story Mode that didn't actually have replays/deaths being created/saved (overworld, home, seasonal areas).
  • Pressing the back button while performing any dropdowns or popups are open in Quick Play no longer returns to the main menu.
  • Fixed issue with the colored glow of key blocker (that overlaps with walls) not always autotiling correctly.
  • Fixed autotiling issues with the Level Editor when objects were placed or deleted. Since all autotiling is now working automatically, the Autotile button has been removed from the Level Editor.
  • Fixed issue with graphics not displaying in the installer.
  • Jump buffering at the start of levels now works with controller. It was only working for the keyboard before.
  • Fixed issue with overworld locks sometimes not allowing the player to pass through even though it was unlocked.
  • Fixed bug where pausing the game would cause the controller to maintain its current level of rumble indefinitely.

Known bugs:

  • If "Allow window resizing" is off, resizing the window on the top or left side makes the window move. This seems to be due to how the following GameMaker functions work with windows: window_set_min_width(), window_set_max_width(), window_set_min_height(), window_set_max_height(1).
  • Replays don't display the correct positions when screen shake is applied to the view.
Changelog v1.5.1 - v1.6.0 - Heart Achievements & Quick Play Story Mode Levels

Changelog v1.5.1 - v1.6.0 - Heart Achievements & Quick Play Story Mode Levels


The latest two updates have brought a lot of character to The True Slime King. In update v1.5.1, we add heart achievements. In v1.6.0, players can now...

Changelog v1.5.0 - Seasonal Content and Amulets

Changelog v1.5.0 - Seasonal Content and Amulets


The True Slime King has been updated with 20 new levels and an assortment of amulets you can collect throughout the story mode to aid in your progression...

Changelog v1.4.0 - Expanded Options Menu

Changelog v1.4.0 - Expanded Options Menu


Update v1.4.0 brings a bunch of new exciting options features to The True Slime King. In addition, a lot of the code has been cleaned up to make things...

Changelog v1.3.1 - v1.3.4 - Bringing life to the game

Changelog v1.3.1 - v1.3.4 - Bringing life to the game


I've been hard at work to bring The True Slime King closer to full release. Check out what's been going on the latest updates, including new goo, new...

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The True Slime King Alpha 1.3

The True Slime King Alpha 1.3


Precision platformer where you play as a slime with the goal of reaching the goo pile at the end of each level to become stronger and stronger until you...


So I was just sitting down playing this for a while, I really like how unique a lot of the mechanics are, the sticking to roofs and such is a really cool idea!

I'd say this is going pretty well, I just have a few recommendations to consider as you progress:
-Maybe use space bar for jumping/enter for selecting levels. With jump and level select both bound to the "j" key I didn't figure out how to do either until I went through pressing every button on my keyboard. Space is often used for jumping because your thumb is usually resting on it, I'm sure you have your own reason for using J so maybe just an option somewhere in the finished game?

-When it came to selecting levels I had no idea what to do, tried clicking, pressing lots of buttons, if there was a prompt to say "j" is to select that would be fine, but if you're not going to prompt you should probably try using keys people will think of sooner.

-With the blue slimes, the introduction to them feels a bit unneeded where it is, it's important to teach your player about them, but maybe in a section where it would feel more meaningful.

Overall this is looking like a great game and I hope you get to finish it because I'm sure a lot of people will enjoy it! Best of luck!

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Josh_Penn-Pierson Creator

Thanks for your input! There's a lot of stuff I want to implement in the game and a lot I want to improve. I'm definitely going to take your comments into consideration.

I think the next thing I'll work on is making the the controls more obvious or include some kind of tutorial. I'm also going to implement custom key bindings at some point. I originally was using "J" for jump because the character originally had a few powers they could use, so I had them under "K" and "L", but now there's no real reason to have the default jump button be "J".

Reply Good karma+3 votes

It's no trouble at all!

Yeah, even while you're in alpha states obvious controls or tutorials can be pretty important for the sake of testers. The alternate powers makes a lot of sense as to why you'd choose those buttons.

But yeah this game looks like it will become a really fun platformer as you continue development, I'll keep an eye on it to see if there are newer builds to test at later stages as well.

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