So first of I’d say try to build the game in layers. So as was said before above me try to have layer 1 be your character, the combat mechanics, heal/stamina/damage mechanics, and a level (small arena) with an enemy/boss.
Then on to layer 2 by slowly building upon that and add an inventory, an additional armor/weapon set, heal/damage items, ring that boosts a stat and so on. Whatever you feel like adds value to your game and the gameplay.
Then add layer 3 by creating a small enemy or a second boss that you can fight in the finished arena or in an (new) additional level. Maybe connect the levels and allow the player to travel between them.
You get where this is going. Try to take small steps and see how long it takes and what you had to do. There’s more to it than you’d think beforehand. A group of students in 4 years could make a great game, but you’d have to learn programming, animation, artwork, textures/shaders, sound effects /sound track, UI design, game design and there’s even more on the marketing and business side of things.
There are AAA studios who try to replicate the Dark Souls and Bloodborne games and who ‘fail’ so make sure you’re not just trying to recreate a game you love to play that took a professional studio years to make. Think hard about what you want your game to be and how that’s going to compare to other games.
Just to give you an impression of those games, there’s Lords of the Fallen, The Surge, Necropolis, Sinner: Sacrifice for Redemption, Vampyr, and these are just the ones on my radar. You’re also competing with other ‘hack and slash’ games or even RPG’s such as The Witcher, so your game better have one hell of a unique selling point to stand out.
Well, this turned out more ‘scary’ than I intended, but my advice is to try to get that ‘layer 1’ finished, see how much time and effort that took all of you, if you’re all still on board after that and go on to layer 2, and so on. Don’t fall into the trap of ‘sunk costs’ where you feel stuck to the project because you already invested so much. You’re students from what I understand so take risks, learn, and don’t be scared to ‘fail’ because that’s also a learning experience.