I liked Ikaruga until I tried chaining. Now I think that game is garbage. Actually, outside of the 4th and 5th stages, it is garbage.
And yes, I hate the UFO power system. ReimuA, ReimuB, MarisA, and SanaeA are completely useless for stages. ReimuB,MarisaB, SanaeA, and SanaeB are useless for killing bosses
No other Touhou relies on clipdeaths to screw your game up nearly as much as this. SA completely fair. MoF, mostly fair. IN, mostly fair. PCB, mostly fair. EoSD- more fair than UFO but also has the issues of random boss movements sometimes leading to impossible patterns. HRtP is agreed on as BS for anyone not in denial, SoEW is known for BS moments, PoDD Lunatic is BS. Very little BS in LLS or MS.
Don't get me started on UFO's power system which will lead to having to time out most things while trying to practice and makes actual runs not fun along with the crappy deaths. The only other crappy power system in the series is in SA, and only for Marisa/Alice.
Oh, and here's one most of us can agree is bullshit. PoFV Lunatic AI, especially Shikieki.