For a story trying to be true to comic book tropes, not too bad, IMO. The problem with origin stories is that they’re usually too detailed to treat well in a TV series - The director feels the need to get on with the main story. Not something that’s likely to be overcome any time soon for these kinds of stories, unless they told the origin in flashbacks over the season, but that runs risks of its own.
Chess is a little too subtle for a comic book, thuogh he’s got great potential in a less action-oriented storyline. OTOH, Scales is a it too much like dumb meat for his name - Not nearly menacing enough for his role in any kind of story. Cain has great potential, but was played too crudely - He could fit a LOT of places - could be really, really menacing used right - but was wasted in this opener. They made him too physical for a poisoner.
Some good lines, some good humor in places, felt a bit rough - too slow in some places, to rushed in others, failed to build any hard suspense. The few times they started to get close, they backed off.
Over all, I’d give it a B-, with potential to rise to a B+ with a little smart work.