Me and my housemate are giving the jam a go. It’s our first time doing a jam, but it can’t be THAT hard, right?
Right?

Probably using Unity, GIMP 2.6, Blender and maybe ModPlugTracker.

Really looking forward to participating in the jam this time around; I’ve actually taken an afternoon to get something done with the tools I plan to use, thus sidestepping the compilation headaches I normally get around five hours in.
(Admittedly, the tool in question is GameMaker, but baby steps.)

So, having actually finshed and submitted something last time, this time, I will finish and submit something competent.

I’m in for this one; ignoring all wisdom to stick with what you know, I’m swapping GameMaker (that I did my last two successful entries in) for Unity (a program that I have historically had Issues with, but I think I’ve got it down now!)

I’m sure it’ll be fine.

Rearrange the title post for a common Ludum Dare declaration.

(At least, if I can get Unity 5 working with MonoDevelop.)

In, but not all the way. Part-way in, as it were. Lurking in the doorway of Ludum Dare, letting in a terrible draught.
In my bag is Pygame (after not having all that much luck with Unity), PyxelEdit and ModPlugTracker if music happens.

Every LD, I will decide that my tooling is holding me back and pick a new one, only to discover that it's my terrible skill in vector maths that is the real problem. Doing this lap again, I chose to use the Bevy game engine this time around; here's some thoughts about Bevy and working with Rust for jams.

First of all, thanks to the invaluable resource that is the Bevy Cheat Book. It's been so good for teaching how to think in Bevy, I'd check it every time I needed to know how to express some concept or clarify something from the official docs; it didn't ever let me down.

Upsides

• I've never worked with an ECS system before, but I can see why these are popular - it's a model that makes it very easy to move from the some concept, like 'I want everything to wobble now', to execution; give everything the Wobbler component, implement wobble_wobblers and feel joy. I put the level progression together in the last 15 minutes of the jam with no pain.

• Because it's in Rust, the game either didn't compile or Worked(tm). I didn't see any odd bugs to work around that were the fault of race conditions or shared access deep in the guts of the engine.

• Performance even in debug mode was great. I tried a similar tech demo involbing just moving points around the screen; it started to chug around 20,000,000 entities in debug mode, way more than you'd need for anything sensible. It felt like I didn't need to worry about performance even when I started needing to nest loops (for each particle -> for each interactable, ect). Could try using the inner join to start modelling particle-particle interactions and see how far the engine can be pushed.

• After some messing around, it compiled to a very distributable wasm build; no bloated Unity player needed. Thanks to Erik Horton's very useful Itch page framework here.

Things to watch out for

• Geometry. The biggest time-sink I had was doing some simple 2D rotations and checks. The standard Transform component in Bevy assumes that you're going to be working in 3D, and hence has a rotation component that needs a Quaternion; it took a fair bot of wading through the examples to find the rotate_about_z() func to treat them as a 2d entity. To be clear - none of this was the fault of the engine, I've just been spoiled by Godot's explicitly simpler 2D projects. Just look out for that if you choose to use Bevy. I'm also indebted to this StackOverflow answer for giving me the 'is within an arc' dot-product trick.

• Build times. This is the well-known Rust tradeoff, but oof it is real. First build will take around 10-20 minutes, and you can expect to repeat that for each time you add a new target or dependency; it's 'go have a snack' times. Incrementel compliation is a bit slower than I'd like too; around 20-odd secs from cargo run to game appearing. There's an experimental hotpatching system in Bevy to get around that now, but I didn't dare use it. For some reason, my dev machine was running incredibly slow Sunday evening, and so I wasted nearly an hour waiting for a build I didn't need to do - it is safe to ctrl-c them mid-build, they'll pick up again from where you left off.

• Wasm dependencies. If you're using Rand::rng, make sure you put the following in .cargo/config.toml, NOT cargo.toml: [target.wasm32-unknown-unknown] rustflags = ['--cfg', 'getrandom_backend="wasm_js"'] If you don't, you fall down the hole of trying to implement your own prng out of bits of string and xors.

Tieup

Can't wait to play with Bevy some more, it's great. Feels like it's what I've been looking for for years.