In Tempest Tower, wind is your weapon, and pushing enemies around with your trusty broom can give you an upper hand.
Half Past Yellow on the gentle art of making enemies for Tempest Tower
HALF PAST YELLOW / GUEST BLOG
Apr 21, 2025|7:13 Min
In this Made with Unity guest post, Half Past Yellow shares how they created a unique visual identity for the denizens of Tempest Tower, out today on Steam.
The element of our game Tempest Tower that we get asked about the most on social media is the art style. Specifically, the visual style of our enemies. There just seems to be something in how they look, fans repeatedly asked how we are achieving such a “crisp” and sometimes “clayish” look. Today we are diving into exactly that.
Return of the lost Peepers
Meet the Peepers – the endearing little eyeball creatures that inhabit the world of Tempest Tower, and a kind of representation of consciousness. They always seem a little lost and “in over their eyes,” like they need a little help to cross the road or figure out where they’re going.
These little guys were looking for guidance in a previous, unfinished project. We liked them too much to leave them behind and felt they deserved the spotlight (and maybe the rescue!) they never truly received.
Peepers were a tiny bit less distressed in the unfinished first-person puzzle game where they originated, but in Tempest Tower, they were already being chased by Anti-Peepers during the very first enemy concept iteration.
Creepers: Crafting the Anti-Peeper
As Tempest Tower is a tower defense game, enemies are essential. Lots of them. Our first concept was a direct counterpoint to our vulnerable Peepers: the Anti-Peeper. If Peepers represent consciousness, these enemies would embody its absence: hollow, vacant-eyed beings acting without clear intent.
However, the first enemy we designed for Tempest Tower had a crucial gameplay requirement: It had to be fun to jump on! This jumpable section also needed to be visually distinct, clearly signposting it as a weak point. Through some design exploration, we arrived at a soft, bounceable sac on their back – inspired by the strangely satisfying urge to pop things like ripe pimples and other pus-laden annoyances. True evil, yet with an undeniable call to action!
Merging the Anti-Peeper with something slightly more jump-enticing resulted in the Bounce Enemy.
As development on Tempest Tower progressed, new threats emerged, like the Peeper Snatcher – small, irritating foes focused solely on consuming Peepers. For these nuisances, visibility was key. We emphasized their mouths with pouty lips and used bolder colors and contrast to make their standout feature ‘pop’ even with their small size on the screen.
When we created the Gunker, a nasty foe that covers turrets in slimy gunk, we applied a similar visual language: no eye sockets, focusing instead on mouths and tentacles to emphasize their soft, slimy nature.
Meanwhile, feedback on our initial Bounce Enemy revealed an unexpected issue: its design was triggering trypophobia for some players, especially when many appeared at once. This feedback, on top of the dated direction, prompted us to redesign the Bounce Enemy. We incorporated the updated color palette and contrast used on newer enemies and leaned into a softer, fuller look. The goal was to make interactions more satisfying – inviting players to jump on and squish them – while ensuring they still read as a clear threat.
Here is the final design of the three basic enemies, and while you might not want to put your foot inside the Peeper Snatcher’s mouth, we promise that you can jump on all of them in one way or another.
Making them shine: Materials and shaders
Achieving the right look for Tempest Tower’s enemies involves a few key techniques in our materials and shaders, crucial for readability in our top-down perspective. These elements are the biggest contributor to the comments we get on social media because they elevate the enemy designs with a unique style that you can’t quite put your finger on. Here’s a peek under the hood.
Lighting
Instead of relying purely on standard lighting, we use a “ramp” texture that dictates how light transitions into shadow on a surface. This gives us fine control to create sharp cartoonlike bands (like we have for characters and enemies) or soft transition without much contrast (which can work well for less important background elements), which is both important to our stylized look and a bit more flexible than basic light.
Glow
To make our creatures feel less like hard plastic and more organic or squishy, we layer a couple of effects:
- Curated glow: We use a dedicated texture map to control emission – making specific parts like pustules and tentacles appear subtly self-lit. This creates a curated “faux subsurface scattering” or internal glow, helping features pop and adding perceived depth beneath the simpler ramped lighting.
- Rimlight (MatCaps): To help enemies stand out regardless of the main light source, we use “MatCaps” (Material Captures). It’s like overlaying a pre-baked lighting setup based on the camera view. We primarily use this to create an artist-controlled rimlight effect, helping to define enemy silhouettes.
It’s important that the player can easily tell the difference between enemy types so they can engage with them properly.
Probe lighting
A reflection probe near the player captures a 360-degree view of the surroundings. We use this captured image to add subtle, ambient light to enemies and other objects nearby. To maintain performance, the probe render uses a very low resolution and doesn’t update frequently. It also fades between renders, ensuring visual changes are subtle and smooth. Our shader adds the probe’s render and includes an option for a Fresnel mask, which allows us to apply the effect, primarily to glancing angles (the edges facing away from the camera). This provides a subtle ambient contribution that helps tie elements together, reacting to the environment in a uniquely stylized (and not very accurate) way.
Should you find yourself standing on a huge colorful cube, the probe light is not so subtle anymore.
The final art style of Tempest Tower combines all of these techniques. We hope that we found just the right amount of glow, softness, and blubber in the material to make jumping on ‘em feel irresistible!
Looking ahead: The value of enemies and new worlds
Of course, the world of Tempest Tower won’t stay confined to just one environment forever. As we conjure up new worlds (and Peepers!) for players, a fresh challenge emerges: How do we keep our enemies visible and distinct against entirely new backdrops and lighting conditions? New zones mean new color palettes, different ambient lighting, and potentially wildly different visual themes.
Our current shader gives us a solid foundation, with the techniques described above. But new palettes mean new potential clashes where enemies might visually blend into the background. To remedy this, we rely on our trusty value chart! When we make new graphics, we always try to fit the new elements within the chart (for now, we only do this with textures, but why stop there!?)
We make sure that the grayscale value of the color texture is within its defined limits, as shown on the chart. This ensures that the background never has too much attention-grabbing contrast, while characters and enemies are allowed to stand out.
But don't just trust these values blindly...
Check out Tempest Tower today
If you like the look of Tempest Tower and want to test out your Creeper trampoline skills, then you’re in luck! Tempest Tower is out now on Steam, there is even a demo available so you can try before you buy. We hope to see you out there, saving Peepers and keeping Trip Space Creeper-free.
Thank you to Half Past Yellow for sharing this behind-the-scenes look at the enemies players will battle in Tempest Tower. Explore more Made With Unity games on our Steam Curator page and get more developer insights on Unity’s Resources page.