Home / Games / Theta and Paralldox on Worldlines
Theta and Paralldox on Worldlines
A lovely logical puzzle game about the many-worlds interpretation and quantum mechanics.
What players say
Steam review score and the most-helpful voices, which may include critical ones. Score via Steam as of 2026-09-25.
“IT'S TORTURING ME. IT'S BRUTAL. I LOVE IT”
— a player, Steam review · 34 hrs played“Excellent puzzles: difficult, but easy to get an overview of so your time is spent solving and not deciphering what the puzzle is. The music loop gets old very fast, though.”
— a player, Steam review · 14 hrs played“50% simultaneous multi-agent movement (made interesting by the left turn rule) and 50% madness.”
— a player, Steam review · 73 hrs playedPlayer activity
Monthly average concurrent players. Live data self-collected from the Steam API · history through 2026-08 via SteamCharts.
Achievement stats
Global completion rates across all Steam players — a data view of how far people actually get. Source: Steam official stats · as of 2026-09-26.
Price tracking
US-region pricing (USD), sampled twice daily by our own tracker since 2026-09-26. Steam prices vary by region — always confirm your local price on Steam.
Regional prices at last sample, in local currency — Steam sets each region's price independently.
Cheapest → most expensive, converted to USD at ECB reference rates (2026-09-25). Relative comparison only.
Latest official news
Developer announcements via the Steam news API — links go to the original posts. More across all games on the news hub.
V1.1.0 Update
Remove levels 5-7 5-8 5-22 in old version， Rearrange the order of levels between 5-7 to 5-17 Add new level 5-20 Virtual Image Change level current5-8, 6-14，6-17 Fix Sliding on ice and stop by the box
V1.0.9 Patch #1
In the previous update, due to an oversight, levels 1-10, 1-11, and 1-14 accidentally reverted to an earlier version. They have now been restored to their correct state. Sincerely apologize for the in
Update V1.0.9
Added new level 3-9 (The previous 3-14 has been renumbered to 3-A; previous 3-9 to 3-13 have been shifted forward accordingly) Slightly adjust level 1-13, 3-21, and 5-4
V1.0.8 Update
Fix UI Adaption in some resolution Now accept undo button(Z/GamePad B) to back in menus Fix a missed note
Screenshots
Official Steam store screenshots — click any shot to enlarge.
Facts & details
From the Steam store record, snapshot 2026-09-25.
| Genres | Indie |
| Player tags | Puzzle · Sokoban · Logic · Time Manipulation · Cute · Abstract · Surreal · Casual · 3D · Singleplayer · Indie · Top-Down (Steam store community voting) |
| Features | Single-player · Steam Achievements · Full controller support · Custom Volume Controls · Keyboard Only Option · #category_playable_at_your_own_pace · Playable without Timed Input · Save Anytime |
| Languages | English, Simplified Chinese, Japanese |
| Controller | Full support |
| Achievements | 28 |
| Official site | https://xexlax.itch.io/paralldox |
Minimum system requirements (PC)
Minimum: Requires a 64-bit processor and operating system OS: Windows 10/11 Memory: 4 GB RAM Storage: 200 MB available space