Note: this involves blockchain VMs. If that's a dealbreaker, feel free to skip. I get it.

I've spent 8 years working on RISC-V VMs for blockchains, recently also contributing to ZK VMs. Modern blockchain VMs are drastically more powerful, and I'm curious how far we can push them. I started porting real game logic to blockchain VMs, running game loop, physics simulation, collision detection, etc., on blockchain VMs. So far I have:

* Teeworlds to CKB-VM: https://xuejie.space/2026_06_16_teeworlds_on_ckb/

* One Hour One Life to CKB-VM: https://xuejie.space/2026_06_29_porting_one_hour_one_life_ga...

* A small ray tracer to Jolt ZK VM: https://xuejie.space/2026_07_10_cpp_ray_tracer_on_jolt_zk_vm...

Source is available for 2 of the 3, I need to clean up the OHOL one.

Some context: CKB-VM [1] is a RISC-V virtual machine I designed for Nervos starting in 2018. Jolt ZK VM [2] is a zero-knowledge virtual machine developed by a16z. Both execute RISC-V code, but due to different design, Jolt ZK VM is a much faster CPU than CKB-VM.

Technically this is a fun challenge. Many techniques I used resemble game development tricks from the 90s on game consoles: fixed point math, banked memory in ROMs, aggressively inlining tricks, etc. I want to push to see where the ceiling is. Right now I'm trying to get a Godot [3] + JoltPhysics [4] game loop running on Jolt ZK VM.

Happy to answer questions about the VM internals, the porting process, or anything in general.

[1] https://github.com/nervosnetwork/ckb-vm

[2] https://jolt.a16zcrypto.com/

[3] https://godotengine.org/

[4] https://github.com/jrouwe/JoltPhysics