No division, no floating point, only 8-bit multiplication and addition, no pipeline, no cache, no MMU, no preemptive multitasking, very inefficient for higher level languages (even C). But you would get about 450 of them for the number of transistors on a 486.
But it was fast, with the smallest instructions taking 2 cycles (one to read the op-code, one to execute). A 1 MHz 6502 is considered on par with a 3.5 MHz Z80, overall.