There was no campaign mode when I last played this IIRC, so I will try that first. The VN-like parts are neat but please let me click through the dialogue if you're not going to have VAs, it's just wasting my time otherwise. On that note, I didn't pay attention to the in-level dialogue at all while playing. I'm not gonna stop playing to read whatever's happening, I suggest either giving the characters voicelines that I can listen to as I move or cutting the feature entirely. I see that you added new sprites for the character view, but, uhh... the damage sprite isn't good. It deviates from the style so much that it's offputting.
The game is very easy, you can strafe around enemies and use the two main weapons to take care of nearly any threat. Like GorriDev said, it feels underwhelming and doesn't force the player to use the mech to its fullest. Frankly, I don't even know what the items do nor how to use them. The only point where I was close to death was when I first encountered the sniper enemy: it's a little bullshit since its aiming laser is not indicative of where its bullet will actually land. It also seemed to instantly fire at me when I first saw it but I might be misremembering, if that isn't the case then give it a warmup period.
Not sure what's up with the Abovespace level, we Getter Robo/Gurren Lagann now? Anyway, the campaign is alright but feels aimless. The level design needs some more intricacies to be engaging, there's only so much mileage you can get out of wide long hallways. Some more objectives would be nice, e.g., protect this thing, stay alive for X amount of time, etc.
It feels like you're getting ahead of yourself to me. I think you should perfect the gameplay core, i.e., the mech movement and combat, and only then start making mountains of content. Either way, I'm eager to see where the game goes.
Most importantly, I didn't see my game's thumbnail anywhere. You can consider yourself my enemy now.