So, I’ve described the geologic strata in Deep Time, and the geochemical ores you can mine there, but I haven’t written about how you get to those places and dig up those things. This is a game, so let’s talk about game mechanics.

Deep Time is a 2D side-scroller in the vein of Terraria or Minecraft. The world is built out of (mostly) square blocks arranged on a grid, which can be hit with a pickaxe (or similar implement) to put them into your inventory, and later on placed back into the world in different configurations if you desire. The initial arrangement of blocks is procedurally generated, with rarer and more valuable minerals found further down. The purpose of the game is to dig as deep as you can, extracting minerals to turn them into money and equipment upgrades that increase your ability to dig even deeper.

Deep Time is designed to be playable primarily with a controller. Although a point-and-click mouse interface provides precision for block placement, in my own daily life I already use a mouse quite enough for work and find it more relaxing and quintessentially video-game-like to switch to holding a controller specifically for playing video games with.

Movement

Something I really like about the early game in Terraria is how, before you get the grappling hook, you genuinely have to treat caves with caution: you’re limited to setting up ropes to navigate vertical spaces and can’t always see how far down a drop is, so even a single careless descent can lead to a sudden death. I want to spend more time in that zone of play, where caves feel the way they do in real life: dark, cramped, and dangerous. Likewise, climbing should feel physical and effortful: whenever you’re holding on to a rope or a ledge, you should have to hold down a button not to let go. I’m considering doing something similar for crawling through tight spaces, although that’s a less fully-formed concept. That aside, the equipment would be unlocked along an upgrade pathway as follows.

Rope

The default means of traversal. Essentially climbable blocks you can set.

Climbing Gloves

Treat all blocks as climbable blocks, still requiring a button hold.

Grappling Hook

Cling without holding a button.

Boost Gear

Gain a double jump.

Mining

Like with movement, I want to add some interesting friction to the process of mining blocks. I’m not trying to make it frustrating (that’s not fun, and I principally want this game to be fun more than realistic) but it should feel tactile in the way that climbing does.

Fracture Drill

Because vibrations in solid matter can be modeled as quasiparticle “phonons”, they follow the same underlying rules as photons: as such, your “drill” is actually a magitechnological device that acts as the analogue of a laser but for crystalline defects in rock, firing a beam of cracks through whatever you press it against. It drills adjacent soil blocks as long as you hold down the button – I could make you press repeatedly until you upgrade it into a continuous hold, but that seems more annoying than is worth it. Upgrades include drilling in half the time, drilling stone (and then metal) blocks, and drilling as a toggle instead of a hold.

Tesseract

A fourth-dimensional quasicrystal that’s bigger on the inside, explaining why you can carry a ludicrous number of blocks with you. Upgrades to have more slots, be able to hold liquids, and letting you hold radioactive/dangerous things in your inventory without harm. Part of me wants to avoid giving this to the player in favor of a crunchier, less effortless form of inventory management, but it’s hard to do that without making things tedious.

Scan Drone

Each miner is given a robotic “fairy”, a small floating device made of centimani (computing and hologram projection) and orichalcum (electromagnetic hover) that acts as both an assistant and a spy, recording everything you do in service of the organization you work for. Its basic function is similar to the scan visor from Metroid Prime: when near a scannable object, hold down the button until a meter fills to gain the lore entry associated with it. Most things in the game can be scanned in this fashion, contributing to an encyclopedia completion percentage. The drone can be upgraded to also be able to send a ping in a radius around you (revealing the locations of ore and creatures), translate ancient scripts when scanned, and show the direction of waypoints you’ve locked on to.

Combat

Although I’m aiming to make combat relatively less common than many similar games, the threat of hostile creatures adds to the gameplay so there will still be random encounters and a few bosses. Enemies are fairly rare but powerful enough not to be ignored, often more like puzzles to carefully avoid – sort of like enemies in Spelunky. You have three main tools to do this with.

Force Blade

A glowing sword that briefly manifests near you to cut nearby objects – the basic melee weapon. Can be upgraded to deal more damage, attack faster, and attack farther. Also used to cut down trees and the like, with an upgrade that makes it selectively not cut non-enemies.

Mass Driver

A pistol-like magitech coil gun that launches small iron bullets. I hate having to maintain supplies of ammunition in games, so the mass driver requires a reload action every few shots (I’m thinking three by default) but doesn’t run out of ammo. It fires fast and accurately, with no range limitation save for the inherent narrowness of the underground environment. Upgrades increase the clip size and damage per shot.

Energy Shield

Makes you invulnerable to most attacks as long as you hold the button to keep it out, facing in the direction you’re standing. Upgrades make it protect from every direction, retain invulnerability against special attacks that would normally pierce it, and parry attacks back with exact timing.

Base Building

There will, of course, be base building mechanics. Making entire towns of villagers wouldn’t really fit the theme, but you could certainly build lodgings for yourself and a few other named miner NPCs – since they would presumably be coming and going on their own delves, I imagine it would be less like a person who lives there and more like a room where NPCs could randomly spawn to trade with. Amenities would include the familiar spread of beds to sleep in (restoring health), boxes to keep items in, workbenches for making equipment, and so on. I’d like to incentivize the creation of outposts at different geologic strata – I’d accept back-to-base teleportation for QoL reasons, but it shouldn’t be easy to go all the way back up, there should be a sense of depth and distance created by the difficulty of ascending from the hole you’ve dug yourself into.