Spireline

Two spires, one multi-lane battlefield, and neither side ever stops fighting.

Your Spire stands on one end, the rival Spire on the other. Waves pour down both lanes at once, and both towers open fire on their own the instant a target's in range, no clicking, no aiming. Your job is to make your side hit harder, survive longer, and out-climb the other one, run after run.

Waves spawn on a fixed schedule and the sim keeps running while you're away, so you come back to progress, not a paused screen. Watch a fight and you'll see units clash across two lanes, towers open up, hits land with real feedback. Walk away and the depth counter keeps climbing regardless.

How a game (run) goes

You start a run, waves come in, your Spire and the rival Spire trade damage across both lanes. Depth increases as you survive. When your run ends, whatever you banked converts into permanent upgrades on the tree, so the next run starts stronger. Level select lets you jump to a specific world and level once you've unlocked it. You'll land on a title screen first, with a settings menu if you want to tweak anything, then it's straight into a running ladder.

What you get

• Two-lane simultaneous combat, your Spire vs. a rival Spire, both firing automatically
• A depth-based wave ladder across worlds and levels, with a level-select screen once you've cleared ground
• A permanent upgrade tree, unlocked from what you bank at the end of a run
• Idle progression: waves keep going and depth keeps climbing while you're not actively watching
• Visible combat feedback on specials (cleave, execute, pierce effects fire and read on screen mid-fight)
• Deterministic simulation under the hood: The same seed plays out the same way every time

We're not going to claim more than that. Scene art (environment props, floor, set dressing around the two Spires) is mid-rework right now; screenshots below are marked with what they show honestly, and this section gets a pass again once that art lands.

AI Disclosure: AI assistance has been used.
Spireline is built by one person with the assistance of AI coding tools (Claude, primarily) for some share of the implementation, primarily for code review and dialogue. Design, direction, and every single shipped decision are mine.

Free. All of it.

Every wave, every world, every tower, the whole upgrade tree: None of it sits behind a paywall. If you never spend a $ here, you're not missing anything the game needs you to have.

I built Spireline solo. If you liked the game enough to click through to this page, thank you, whether or not you buy anything.