Just personal scratch.
Advised, possible spoilers.
Opinion & Informal
Art: 5/10 It was okay. The characters looked like they were supposed to from their respective series but then again 70% of their bodies were either covered in water or censored by convenient steam, ignoring that they were all naked and neither were in their usual generic school uniforms.
Panel Progression: 5/10 No border cutting or impact art so it was just average. Panel progression wasn't confusing and didn't make anything confusing.
Characters: 5/10 All the poorly written characters were there, yeah.
Plot: 4/10 Why was this crossover even necessary?
Development: 4/10 No development. Adds nothing to each of their respective
universes or characters both plot and character-wise.
Conclusion: 4/10 Well, at least it didn't create any questions or new plot points to urge me into reading more of those meh series.
Overall: 4/10 When big breasted animals and insects need that extra bit more character development that their main series failed to do.