#netcode is a circle of hell

[mistakenot4892]

Progress on my little game project.

It looks extremely simple (because it is, really) but this is a client-server engine built on the Monogame rendering/input framework and the C# Socket class. I've never really worked on netcode before outside of one semester at Uni so this has been an interesting challenge.

With a regular single-player local game, you can update everything on the fly as frequently as your renderer refreshes (120 times a second for my render layer). You don't need to have a specific authoritative (accurate and real) world state, because definitionally, the world state that exists is authoritative.

With my build, even local singleplayer is using a server via localhost, so prediction and interpolation are required to make inputs feel snappy and movement feel smooth. The server runs at 50ms intervals, so twenty times a second, which means if I just use the world state at any given point, movement is going to be choppy and inputs are going to be delayed. I need to interpolate (smooth out) movements across the 50ms intervals, and I need to run my movement and physics logic on the client to hide the 50-100ms latency between inputs and action on the screen.

Valve has some great documentation on their model which I have been using heavily, and I am currently trying to implement Gabriel Gambetta's writeup on client prediction so my character stops jumping around wildly on my remote test server.

The other big challenge at the moment is getting my serialisation and marshaling logic to work consistently. I am using MessagePack for serde, which is a lot easier than trying to write my own serde and handle Endianness and network byte order and whatnot, but I am struggling a bit with debugging bytestreams on the remote server. I may need to learn to use Wireshark and equivalent to work out what the hell is going on under the hood.

It has been a lot of fun, even if some of the bugs have been extremely frustrating. I am hoping to build this out into a general purpose engine for future game projects, but even if I stall out I have learned a ton about netcode for games.

[satoshi-mochida]

mino_dev will release bullet hell-based magical girl battle game Maiden & Spell for Switch via the Nintendo eShop, the developer announced. It will be published by Nippon Ichi Software. A specific release date will be announced soon.

Maiden & Spell first launched for PC via Steam in February 20.

Here is an overview of the game, via mino_dev:

About

Maiden & Spell is a bullet hell-based, one-versus-one battle game. Heavily inspired by Japanese shoot ’em ups and doujin games, it features an all-girl cast of colorful characters fighting each other with bullet hell patterns. In addition to local 1v1 matches, it features a fully realized Story Mode with unique boss fights to defeat.

Unlike other one-versus-one fighters that have some bullet hell elements, Maiden & Spell seeks to capture the true spirit of bullet hell in its combat. There are no melee attacks; everything is magical bullets. There is no blocking or parrying, instead there are “bombs” on cooldown and hitboxes that are only about six pixels wide. Your victory relies on successfully dodging the opponent’s danmaku patterns… all while throwing out your own!

Story

In search of a mysterious jewel, a group of adventurers plunge the depths of what is rumored to be the most dangerous dungeon in the world: a vast abyss known as The Great Circle. To their surprise, they find the dungeon mostly devoid of monsters, and housing the ruins of a civilization long forgotten by the world.

As they delve deeper into this mysterious underground world, they begin to uncover the secrets surrounding the vermilion gem they seek, the monsters of The Great Circle, and the lost city once known as the Kingdom of Stars…

Key Features

-Rollback Netcode – Yes, there is online and yes the netcode uses rollback.

Hang out and play with your friends in public or private lobbies.

​-Eight Cute and Colorful Characters – Each with extremely unique magical attacks and abilities.

-Versus Mode – Play in local one-versus-one matches against computer or human opponents.

​-Story Mode – Play as one of four characters against a mix of battles and special, story-specific “Magnus Attacks” that truly test your bullet hell skills.

Dive deeper into the abyss and learn the secrets of the Kingdom of Stars.

Playable on four different difficulty settings: “Very Hard Mode” truly pushes bullet hell combat to its limit.

-Training Mode – Test abilities and move combinations to hone your skills.

-Extras – Such as a Music Room to listen to the soundtrack and Ultra-punishing “True Magnus” attacks.

Watch a trailer below.

[clickbliss]

Maiden & Spell Review

by Amr (@siegarettes)

Maiden & Spell

Developer: mino_dev

Publisher: mino_dev, Maple Whisper

PC

Take the elaborate bullet patterns of modern STGs, give them to adorable fantasy monster girls, then combine them into a fighting game and you get Maiden & Spell. A niche within a niche, Maiden & Spell is part of a line of surprisingly varied shooter-fighting game hybrids, following in the mold set by G-Rev’s Senko no Ronde. As you might expect from a combination of such obsessive niches, Senko no Ronde was a maximalist game, one with highly detailed mechanics and obtuse nuances that required serious effort before you could begin to understand what you were playing. 

Compared to its contemporaries, Maiden & Spell is stripped down, focused on immediate communication. It turns an intimidating genre into an inviting one, one you can show to your friends and immediately have them understand. 

Maiden & Spell’s colorful designs brings to mind Akihiko Yoshida’s work on the Final Fantasy series, and the bold lines and contrasting colors make clear where threat and safety lie. Each character is assigned a specific color, and their hitboxes are on display to make sure there’s never confusion to where you can take damage.

Likewise it tosses away the flashy and elaborate HUD of its inspirations and uses familiar RPG-style skill icons, complete with cooldowns. It’s much faster to parse than the different intersecting circles and layers of meters that have become the genre standard. Health bars are even tossed out, instead using a system of hearts and cards, signalling how many hits you can take before you lose a life and the round resets. Each hit is accompanied by dramatic text declaring HIT and BREAK, making it clear what happened. 

If fighters like Senko are all out brawls, where success is measured in cumulative blows leading to the KO, then Maiden & Spell is fencing, focused on stepping around your opponent and forcing them into a corner for that single lethal hit. Fighters can get chaotic, and sometimes you’ll find yourself knocked down before you understand what exactly hit you. Maiden & Spell retains the chaos that makes them so fun, but presents it so that its clear how exactly every hit happened. 

To that effect, Maiden & Spell gives you plenty of ways to drive your opponent into a corner. There are four characters, each providing their own unique moveset and strategy. Each face button responds to a skill, with another button used to slow down for precise movements and focus your attacks. Skills are broadly categorized into direct attacks, wide attacks, and offensive and defensive skills, though those categories aren’t necessarily exclusive. 

Direct attacks force opponents to move, while wide attacks generally only work against moving opponents, so combining the two is key to putting your opponent in a bad situation. Once there, offensive skills can be used to secure the point and create an inescapable situation--unless they can neutralize it with their defensive skills. The interplay of these moves gives clear utility to each of them, creating an RPG-esque rotation you use while focusing on attempting to position yourself outside your opponent’s traps. 

Exactly how those skills play off each other changes wildly between characters. The Hero of Frost gets in fast, with a powerful dodge roll that gives her enough invincibility frames to get out of most situations. Meanwhile the Lich of Flowers gets more dangerous as the round goes on, with flowers that create hazards across the entire screen, butterflies that act as turrets, and a charge spell that covers the screen in a giant rose. 

Other characters occupy the space in between, with different setups and game plans, and even unique movement options. There’s plenty to play around with and the way that the dynamics work off each other creates a lot of variety in the situations you can set up, or be forced to deal with. 

All the depth in the world doesn’t mean much if you can’t get a game, and on that front Maiden & Spell also happily delivers. M&S uses a lobby system not unlike the ones used by Arc System Works, with various rooms you can walk into to battle with others, and rollback netcode that minimizes stuttering and the effects of lag. I played with a friend from the UK, and despite being all the way in Chicago I only experienced two half second interruptions in over an hour of play, neither which was long enough to cause problems. The rest of the time the experience felt as if we were playing in the same room, with little to no noticeable input lag. I’d had problems with connections in other games with the same friend before, so the implementation of online play here is truly impressive. 

Maiden & Spell does a lot to invite you in, and more to keep you around. Bullet hell and fighting games are two genres with huge intimidation factors, but Maiden & Spell winning combination of colorful fantasy art and adorable characters makes it feel approachable in ways that other entries in the genre don’t. Fighters sometimes feel like they require a lecture before you can understand what you’re looking at, but M&S draws you in and uses familiar visual language to immediately explain itself. 

Maybe this is a strange way to describe a fighter, but Maiden & Spell is a game that radiates warmth. It’s charming, adorable, and every new character and stage is an opportunity to spend more time in its fantastic little world. I loved it since the first played its demo and its final form is just as easy to love.

[mistakenot4892]

Sometimes I talk about my field with people and think ah yes, I have domain-specific expert knowledge of some topics, I am competent in my chosen subject area.

Then I spend three hours trying to work out why my client program is connecting to itself instead of the server and I wonder if I should be permitted on the Internet without supervision.