It's disappointing that this never turned into its own sub-series. I liked how different it felt from the mainline games, with the focus on catching Pokemon being even greater than battling. Being able to simply catch every Pokemon you meet without fighting them leads to a very stress free playthrough. Especially if you enjoy the motion controls for throwing your pokeball (were honestly pretty fun, in my opinion).
It definitely feels like a lot more of a casual, carefree experience than other games in the series - especially Arceus, which while also having a greater focus on catching, is also the polar opposite of this game, with just how dangerous wild Pokemon are - but I think that makes it a good introduction point for new players. Especially with the co-op mode, which makes the game even easier - feels like a "little sibling along for the ride with big bro/sis" add-on rather than a truly, fully fleshed out gameplay style in its own right - but is fun none the less.
Selling that Mew with the $50 pokeball controller - which basically only really works for these game - was definitely a real rip-off, though.p