Cosmo Sling is a 2D space arcade game where players pilot a spacecraft through hazardous space, dodging asteroids, black holes, and other cosmic dangers. This submission includes both Campaign and Endless modes, multiple selectable ships, polished UI, dynamic backgrounds, and improved gameplay and visual effects.
2h 32m 47s logged
Upgrade Devlog - #3
Just completed the game, upgraded the ui, selection of ships and a new gamemode.
i will not add anything to this game anymore. This game is complete for me.
This is the End!
3h 0m 12s logged
Upgrading Devlog -#2
I added nebula that will come and try to block your vision. Also, i added blackhole but its not fully developed yet. You can see this perfectly timed image of the game that will show all of the upgrades
2h 17m 5s logged
Upgrading devlog - #1
I just woke up and decided to upgrade the game and add an endless mode also. I will work on more upgrades like - mutiple ships, game control etc.
This is what has been completed till now:
Endless bg.
Ship movement by WASD.
Asteroids.
Cosmo Sling is a 2D physics-based space puzzle game where players launch a spaceship from Earth and use the gravitational pull of randomly generated planets to reach the destination. Throughout development, the project has evolved from a simple gravity prototype into a polished game with procedural level generation, multiple difficulty modes, accurate trajectory prediction, dynamic gravity physics, sound effects, UI menus (main menu, settings, pause, win/lose screens), camera improvements, and WebGL support. Continuous feedback and playtesting have led to numerous gameplay balancing, bug fixes, UI refinements, performance improvements, and overall polish, bringing the game close to its final release version.
2h 47m 5s logged
After first ship devlog - #4
I have successfully fixed all of the issues pointed out in the feedback. Here’s what i did:
Implemented the core gravity slingshot mechanic.
Added procedural planet generation and difficulty levels.
Improved ship launch controls and aiming.
Made the trajectory prediction smoother and more accurate.
Fixed multiple gameplay bugs (launch, collisions, UI, camera).
Added pause menu, settings, win and lose screens.
Improved audio system with sound effects and music controls.
Balanced gravity strength and gameplay difficulty.
Refined ship movement and collision handling.
Fixed camera positioning and gameplay visibility issues.
Optimized the game for WebGL and browser compatibility.
Resolved UI scaling and resolution problems based on testing feedback.
Added overall polish and prepared the game for release.
Special thanks to @PAPER_01 for following this journey and encouraging me.
53m 41s logged
After ship devlog - #3
Just fixed the win/lose panels.
I’ll add WebGL very soon.
2h 59m 38s logged
After ship devlog - #2
I’ve just fixed 40% of the issues ya’ll pointed in the first ship and tried my best to work on your feedbacks.
1h 52m 30s logged
Marine Odyssey - Devlog #6
There were MANY small tweaks and fixes to do in the game and in the event. I just:
Fixed tentacle rotation.
Added camera shake.
Fixed submarine movement.
Fixed Dark effect.
Adjusted timings.
Debugged some code.
The Marine Odyssey is 20% completed.
Still no UI, audio, buttons etc.
One more thing, please give me some ideas of what can i add besides Kraken, Sharks and Starfish swarm. Or any feature you have in mind that will look good.
1h 46m 9s logged
Marine Odyssey - Devlog #5
Phew…!!
It was a long day fighting errors and adjusting stuff.
What i did is to implement the full Kraken. The old codes had soo many errors and structural issues and was incomplete. So, i had to replace almost everything and also upgraded the gameplan
Some features are still missing though, that i’ll add later.
And yeah, i still haven’t added the sprites and UI, just working on the gameplay.
1h 10m 37s logged
Marine Odyssey - Devlog #4
Been focusing on gameplay systems instead of visuals lately.
The shark encounters are now working, with coral hiding fully integrated into the core gameplay loop. After some playtesting, I scrapped one of my original enemy ideas because it just wasn’t as interesting and started building a Kraken event instead.
The Kraken is turning into one of the game’s biggest moments. Instead of permanent obstacles, giant tentacles will strike from beneath the seabed, forcing quick reactions and precise movement. I’ve also finished setting up the event system that controls the warnings, ocean darkening, cooldowns, and attack sequence. The tentacle system is now being rebuilt to use movement rather than scaling, which should make the final animations look much more natural once the real art is added.
Still sticking with placeholder shapes for now. Getting the mechanics right before worrying about the visuals has been the best decision so far.
1h 33m 8s logged
Marine Odyssey - Devlog #3
Made a lot of progress today.
The coral system is now in place, including hiding zones that the submarine can use to avoid sharks. I also got the first enemy working—sharks now patrol the ocean, chase the player when spotted, and lose interest if you disappear into the coral.
I spent some time cleaning up the game’s structure too, fixing early issues with the camera, movement, and world scale so everything feels much more open. I also scrapped one of my original enemy ideas and replaced it with a Secret event that’s going to be a full event instead of just another obstacle.
Still using placeholder shapes for everything. Focusing on making the gameplay fun first before moving on to art and polish.
1h 48m 52s logged
Marine Odyssey - Devlog #2
Made some solid progress on the submarine game today.
I finished the core movement systems, added an endless scrolling ocean, and reworked the camera so it follows the submarine vertically while the world keeps moving forward. I also cleaned up a few early design decisions to make the ocean feel much larger and easier to build on later. Started working on the coral system as well. The coral foreground now loops endlessly with the environment, and I’m laying the groundwork for hiding mechanics that’ll be used to avoid predators later on.
Still using placeholder shapes—gameplay first, art later.
I’m really excited to complete this game and show it to you all!!!
52m 11s logged
After ship devlog - #1
Started working on the feedback from the first players today. I fixed the difficulty system so each mode now spawns the correct number of planets, fixed the pause menu not appearing properly the first time, and stopped the win/lose sounds from repeating.
I also fixed the music and sound toggles so they stay independent and sync correctly, and optimized the gravity system by caching the planets once per level instead of searching for them every physics frame.
Still a lot more feedback to work through, but the game is already becoming much more stable and polished.
I will ship the game again after fixes and some more firey upgrades.
40m 48s logged
Marine Odyssey - Devlog #1
Just started off this underwater submarine game.
I went through a lot of ideas following the arcady style 2D game and landed on this game idea.
Wait to see the whole game reveal itself
40m 16s logged
Devlog – I’m Shipping Again
My first ship was sent back with changes requested because I accidentally forgot to mention my AI usage in the submission. I’ve now corrected that and am resubmitting the project with the proper information.
There is also a second Hackatime project because I changed the Unity project/company name from Cosmo Slingshot to Cosmo Sling near the end of development. Hackatime detected the renamed project as a new project instead of continuing to track time under the original one.
So the two Hackatime projects are both for the same game:
Cosmo Slingshot — most of the development time
Cosmo Sling — final changes after the rename
This is not a second game or a duplicate project—just the same project being tracked under two names.
I made Cosmo Sling, a 2D physics-based space game where you get one launch to reach the destination planet. Randomly generated planets use gravity to curve your ship’s path, with four difficulty modes ranging from 1–6 planets.
The most challenging parts were building the gravity system, random level generation, keeping the game working across different screen sizes, and fixing scene/UI issues. I’m most proud of getting the complete game polished and shipped with sound, settings, pause/restart controls, and a Windows build.
To test it, download the game, unzip it, and run Cosmo Sling.exe. Click and drag to aim, release to launch, press P to pause, and R to restart anytime.
3h 34m 5s logged
Final Devlog – Cosmo Sling Shipped 🚀
Today I finished and shipped Cosmo Sling!
I completed the final polish, including:
Background music and sound effects
Music and sound toggles with saved settings
Pause menu and win/lose states
Final UI fixes and screen scaling
Game icon and branding
Windows build and final testing
After fixing the last build and resolution issues, I packaged the complete game and published it on itch.io.
Cosmo Sling is officially finished and shipped!
3h 25m 29s logged
Devlog #5 –
UI & Visual Polish
Today I focused on improving Cosmo Sling’s visuals and UI.
Added a new pixel-art settings panel.
Created Music and Sound toggles with blue/white visual states.
Improved the menu’s space-themed design.
Added an infinitely moving space background.
Fixed several issues related to camera bounds, level generation, launching, and missing audio references.
The game is now starting to look much more polished and consistent with its space theme.
4h 8m 4s logged
Devlog #4 – Big Progress on Cosmo Sling
I completely forgot to write two day’s devlog while working 😅. I spent around 3–4 hours developing the game, so here’s a recap of everything I got done.
Project Update
Development on Cosmo Sling has been progressing really well. The core gameplay loop is now in place and the project feels much more like a real game than just a prototype.
Gameplay
Finished the one-shot launch mechanic.
Improved the aiming system with a visual aim line.
Added gravity that pulls the spaceship toward nearby planets.
Implemented procedural generation of gravity planets based on the selected difficulty.
Added random planet sizes and gravity strengths.
Added minimum spacing between generated planets to reduce overlap.
Game Systems
Added a proper Game Manager and Level Manager.
Added win and lose conditions.
Implemented a hull (health) system.
Added boundary collisions with hull damage.
Added restart functionality and pause menu.
UI
Created the HUD to display hull information.
Added Win and Game Over panels.
Added buttons for restarting and returning to the main menu.
Visual Polish
Added planet spawn animations.
Added a launch animation for the spaceship.
Added a pulsing effect to the destination planet.
Added an explosion effect when the ship is destroyed.
Challenges
There were a few bugs along the way, mostly related to script references, gravity generation, and scene setup. After tracking them down and fixing them, the project is much more stable and easier to build on.
Next Steps
The next goal is to improve the game’s presentation by adding camera effects, audio, particle effects, and a more polished background. After that, I’ll focus on balancing gameplay and polishing the overall experience before release.
Overall, today’s session was very productive, and Cosmo Sling is steadily becoming a complete and polished game.
