The game is nicely done, the graphics and sounds are pleasant.
I feel like the item spawn is a bit unfair as it can churn out same parts (e.g. left halves of the glasses) for a long time. That combined with losing money for wasted parts adds some frustration.
In my opinion, removing time limit in favor of slowly increasing conveyor belt speed could provide a bit more potential.
In conclusion, with some polish end expansion (perhaps having more than one assembly step) this could be a cool full-fledged time killer. Good job!