DekuDeals is what I use. It doesn’t have every country, but it has a lot. Some countries like the US have multiple stores listed, such as eshop, Best Buy, amazon, GameStop etc, but for the Australian option (what I use) it only has amazon and eshop to compare. It shows price history, the game size (digital), metacritic score and sometimes how long it would take on average to beat. I wish it had more options for shops in some countries (e.g in Australia adding: EB Games, JBHIFI, Big W etc) but it’s all worked on by one guy to my knowledge. Pretty sure it can send you emails of certain games if you opt in.