There are more assembler dialects than I care to remember.
The 2A06 assembler that people who write NES code (and later on SNES/GB/etc) use has some real quirks: $ prefixes a literal hex value but % is binary, but # in front of that is an address, registers are baked into the opcode (ldx -> load into X), and more.
Playstation folks all just used MIPS dialects which are mostly AT&Tish but the PS2 used an Intel style assembler.
See the AT&T vs Intel syntax since you aren't familiar with assembly:
https://en.wikipedia.org/wiki/X86_assembly_language#Syntax