There is a particular category of game - not a specific genre - that can be called endless. Tetris would be an obvious example, and at another pole there's something like Disgaea. Games where the core idea is so beautifully executed it can be escalated and repeated ad infinitum yet never loses its freshness. Things you could play forever. Devil May Cry 3 is one of the best, and despite its turbo-charged action is the ultimate slow-burner.
At first glance, it's easy to think of Devil May Cry 4 as a soulless cash-in. Between its uninspired level design, confounding camera, and new protagonist who looks almost identical to series' hero Dante, it would seem as if Capcom had drawn too often from the same well. As Eurogamer pointed out in its 2008 review, DMC4 "feels like a high-def re-skin of a 2001 game design". It's no wonder Enslaved developer Ninja Theory has been hired to breathe some new life to Capcom's flagship demon hunter.