Maybe a slower buildup to the first ghost/alien could've worked but I kind of appreciated the fast pacing personally. What I would've liked is the two MCs' relationship sprouting more slowly instead, she's ready to risk her life for a guy whose name she quite literally didn't even know and is obsessed with the nerd in no time. She's clearly supposed to be hot and he's a scrawny awkward geek, so there's nothing to really attract her so quickly.
Another thing, I'm tired of characters getting their super forms from an external source, often an antagonistic one that becomes their buddy. I saw this shit a mile away when he first transformed, not because I'm so smart but because it's the most braindead pattern recognition ever.
Also, the power scaling is retarded, bitch can't walk some stairs but can get beaten to a pulp and keep fighting? Makes no sense. I also get no sense of where characters compared to each other, it's all a bunch of gimmicks and just doing whatever the story calls for at the moment, not a lot of logic involved.
I probably sound like I hate this show but I like it a lot.