Quick answer: Your game fails on low-memory devices because its memory footprint exceeds what those devices have: it runs out of memory and crashes, gets terminated by the OS (mobile OSes kill apps that use too much), or can't load. The footprint that's fine on your high-RAM development machine exceeds a budget phone's or older device's much smaller budget. It's a resource-budgeting mismatch.
Low-memory devices, budget phones, older hardware, memory-constrained consoles, are a real part of your audience, and a game that needs more memory than they have will fail on them. This is fundamentally a memory-budgeting problem: your footprint is larger than the device's budget.
Why Games Fail on Low-Memory Devices
Every device has a memory budget, and it's much smaller on low-memory devices. A game whose footprint exceeds that budget fails there: it runs out of memory and crashes, gets terminated by the OS (mobile OSes kill apps that use too much memory), or can't load. The footprint that's fine on your dev machine (with plenty of RAM) exceeds a budget phone's or older device's much smaller budget. Causes of a too-large footprint: large/uncompressed assets and textures, loading too much at once, not freeing unused memory, and ignoring VRAM limits.
So failing on low-memory devices means your footprint is over their budget, a resource-budgeting mismatch concentrated on the devices with the least memory.
How to Diagnose and Fix It
Measure your footprint and compare it to the low-memory target's budget. In the field, the signature is out-of-memory crashes (or OS kills) concentrated on low-memory devices. Bugnet captures device memory context with crashes and groups them, so out-of-memory crashes correlated with low-memory devices surface as a clear pattern, confirming a budget problem and telling you which devices (and how much memory) you need to fit.
Fix by reducing your footprint to fit the budget: smaller/compressed textures and assets, load only what's needed and stream the rest (often the biggest win), free unused memory and fix leaks, and account for VRAM. Set a budget for the low-memory target and reduce until it fits, then verify on actual low-memory devices. See our guide on fixing a game that fails on low-memory devices.
Failing on low-memory devices means your footprint exceeds their budget. Reduce it, smaller textures, load less at once and stream the rest, account for VRAM, and test on real low-memory hardware.