Developing a "mouse only" Game

So, mouse only. The daddy of FPS, the ultimate tool in gaming to some and to others merely a pointing and clicking device.

For me I see a mouse these days as a combination of a game controller, and a pointing device. Heck some mouses have over 15 buttons! Might aswell be a TV Remote at that point!

In this post I will be focusing more on mouse only gameplay in the simulation/strategy game genres - as I can imagine games like Osu! and other reaction based games are also mouse based games but are very skill based and is a different topic of interest to what I'm sharing here.

I look forward to sharing some of the things I think about while developing my sci-fi game Dead Desert, which is a realtime squad RPG and has a focus on being mouse only.

Crazy mouses and Macros

One thing I always find myself doing with simulation games, survival games, even FPS games is using my mouse primarily when doing "afk", "grinding" or "farming" activities. Some games are built well for this and others you can use macros to further enhance the abilities of the mouse. For example, if I want to explore with just the mouse in an FPS game, I can bind W (move forward) to a macro button on the mouse, and with little effort I can now control the movement of the character with the mouse. You can go further and rebind things like jump, interact but once you start doing more - this is when you need a more macro focused mouse.

Great for simulation, strategy & building games.

Some games are built for mouse only, these are normally seen within a genre like Simulation, Strategy and City Builders. Sure there are keyboard shortcuts; but by large the entire game can be played with just the mouse. And that's great. It's great because not all games require 100% of your attention and 100% of your upper limbs to be active to play the game.

Relaxing

Having a mouse-only game gives your game the ability to be just a little more relaxed at times. To give the player a time where they can play while eating a donut in one hand and playing your game in the other. No stress, no waiting for the best time to eat. Nothing like that at all. Just relaxed, donut-eating-yummy-donut-gaming.

Easier to start. harder to master

Some of the most complicated games out there are mouse only, Stellaris, The Sims and Rimworld. This mouse only experience makes it an actual easy barrier to entry. Sure the game gets more complex as time goes on - but if you can just click around guessing about what you're doing, that's going to be a lot easier compared to - for example - a space flight sim. In most mouse only simulation games this also means your own skills and reactions aren't being tested all the times, you can pause the game - look around and click around - you can mull over a decision before taking it; this essentially turns all realtime games into a turn based game if you consider each second a turn. You can pause the clock after all.

The challenges

So mouse only might be a development challenge your adopting in your game, if you're making a simulation game it might just be the obvious path and only now you're realising everything happens with the mouse. Now it seems simple "oh the game is played on the mouse only" but actually it's not that simple. Just being able to say "press W and Click" makes your code work in 10x more scenerios than "press middle click" which some mouse can still be found without middle click, a broken middle click or the worst of the worst - a laptop where the middle click is annoying to use on trackpad.

And in fact "trackpad" brings me on to another difficult challenge which is when something works with mouse that doesn't necessarily mean it works well with trackpads. Once you start booting your game on Macs, or on laptops you might be frustrated by seeing how the trackpad seemingly does something different on every device. At some point you might think you need to invent your own "gestures" guide for your game but we all know that isn't the right answer.

Lots of little challenges will crop-up over your project like this. You just need to make sure you're considering the game with every decision. Try make it natural, seemless and what they expect.

My tips

• Only use the 3 known mouse buttons, left click, middle click and right click.
• If at all possible, assign middle click to a task which can be achieved another way (e.g. with arrow keys or WASD).
  This is because middle mouse button is often half broken on the mouse and laptops don't handle middle click well.
• Allow mouse buttons to be rebinded.
• Everything must feel "snappy". If a player clicks and drags something it has to happen realtime and work every time.
  This is because if it doesn't feel snappy it feels the same as FPS lag and annoys gamers ALOT
• Still use the keyboard for "power users". Some players will learn every binding to assist in gameplay, so make sure to add them.
  To make a keyboard binding available to mouse users, it could be a "toggle button" on the UI