castle idler
castle idler is a short, relaxing idle tower defense game with no waves. idly upgrade towers, collect coins, and unlock a vast skill tree to defend your castle from a slime invasion.
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deploy a variety of towers along winding paths and continuously upgrade them

progress through increasingly difficult levels with trickier paths and tougher enemies

explore the prestige skill tree: unlock permanent, game-changing abilities that make your defenses exponentially stronger
incrementaldb_verification: soyboygames
| Status | In development |
| Platforms | HTML5 |
| Rating | Rated 4.4 out of 5 stars (35 total ratings) |
| Author | Soy Boy Games |
| Genre | Strategy |
| Made with | Unity, Aseprite |
| Tags | Clicker, Idle, idler, Incremental, Minimalist, No AI, Pixel Art, Singleplayer, Tower Defense |
| Average session | About an hour |
| Languages | English |
| Inputs | Mouse |
| Links | Steam |
Development log
- update 0.942 days ago
- update 0.375Nov 21, 2025
- v0.35 (Demo now on Steam!)Nov 03, 2025
- update 0.1.25Oct 09, 2025
- update 0.1.15Oct 07, 2025
- steam page now live!Oct 07, 2025



Comments
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Thanks for the game. The killstreak is a very good condition for wining the level.
Here is some though when I play the game:
I don't see a reason for using the ice tower. Slowing the enemy doesn't do much since we don't have AOE attack and there is enough enemy for the arrow tower to deal damage constantly. Using the population to buy more arrow tower seems to be a easier better option at most of the game.
Thank you for your feedback! A major demo update is underway for the official Steam demo launch. I've added a new tower and buffed the Ice Tower. To incorporate more strategy and balance the game, I've also introduced a new prestige upgrade that rewards you for using different towers, along with new upgrade paths for each one.
There is interesting ideas and I enjoyed, but some sounds are awful and much louder than the music
The sound effects have been changed in the recent patch.
Great game. I really enjoyed that the castle didn't have health but instead the level just looped repeatedly until you reached your killstreak.
After beating the game normally, I found myself wishing for a "race" mode. In this mode, I would be able to prestige and collect the bonuses in any order (instead of having later ones locked by pre-reqs), so I could try and beat the game in a certain number of loops without all of the bonuses. To that end, it'd be nice if the victory screen showed some stats like time, total number of gems collected, number of times each level was completed and the like. Then I could screeenshot my accomplishments and post them here in the comments.
Even without that, I found it fun to replay the game after beating it and trying to beat all the levels by only focusing on a specific tower type.
Thanks for your feedback! I will add a victory screen that displays your stats/time in the next update.
The game should NOT pause on focus out.
i will fix that in the next patch
it has been fixed
this was very good. i approve. and my approval means far more than the combined feedback of everyone else.
trust me on that, kid.
It's neat, but there's only two types of towers, and one of them is way better. Ice slows down the enemies to keep them in groups, but also it's an area attack, so it synergizes with itself. Eventually you upgrade arrows to deal damage over time, but it doesn't last that long and it's only worth it on levels with few enemies. And the extra wood doesn't help for the ice towers. They don't need a large area because everything groups into the area they can hit, and they don't need permaslow because they're constantly slowing all the enemies, and it's definitely pointless after the first tower.
The poison is actually very strong as well. You easily beat the game with nothing but spamming L1/L2 Arrow towers relying on bouncing poison onto everything and melting them, while only upgrading attack speed. Only on the final wave do you even need to touch the base damage upgrade.
Thank you for your feedback! A major demo update is underway for the official Steam demo launch. I've added a new tower and buffed the Ice Tower. To incorporate more strategy and balance the game, I've also introduced a new prestige upgrade that rewards you for using different towers, along with new upgrade paths for each one.