Which part?
The over abundance of spartan cores (valor points as well) is nice, because it doesn't mean that someone playing Halo: Infinite needs to grind out every little collectable in order to unlock everything. The weapon variations are also nice, although the power of a few of them could be bumped down a little, IMO. But overall not so bad considering at higher difficulties you are likely to run out of ammo for it and have to swap to a different weapon anyway.
The max level grappleshot, however, I think is way too powerful. In that sense it's broken, but it's probably either intended to be overpowered or the developers didn't think players would potentially abuse the shite out of it.
Overall, this being 343i's first open world game (it's only not fully open in ~the first half of the game, sort of like Days Gone) and the development troubles that the game went through I'm willing to excuse the relatively unbalanced effect that the open world stuff brings to a Halo game.
After how they managed to finally understand what a Halo game is, even if it isn't perfect, I'm willing to give them the benefit of the doubt that they'll get the balance (power level of the player) right the next time.
Unlike Halo 4 and 5, this actually feels like a Halo game ... but with an open world added to it. And unlike the open exploration area's of Gears 5, there's actually meaningful things to do in the open world exploration areas.
If I have time, I'll probably replay it again without leveling up anything other than the cooldown for grappleshot. And I'll avoid using any unlocked weapons. Also, avoid taking Marines (they are freaking OP as hell with the right weapons) with me in the open world.
Regards,
SB.