>By that I mean missions felt samey
Yeah, you hit the nail on the head - I messed up the game design. My main source of gameplay inspiration was BattleTanx, but later on I pivoted towards PS1's GiTS game, and scrapped most of the subweapons, hoping that depth of the few mechanics that remain can carry the game. Turns out that mechanical depth was mostly a busywork. Tangible, visible upgrades or customisation is what would've kept the player in, it's what I would've personally preferred and it is certainly possible to achieve that in this engine, but it would be way too much work, and I'd rather not waste too much time on GZDoom if possible. So the plan right now is to to make a couple more levels, give it some kind of closure and then focus on learning another engine. That being said, I'm not going to keep the nautical theme either - while I heard some feedback that it makes my project rather unique, I'm not that big fan of it and it makes level design hard so I'd rather make a game about tanks or mecha instead.