One of the last good 2-D shooters made for PSX
The controls were tight and responsive, and the a.i. was challenging (something rare on a medium that depends on patterned attacks most of the time).
I kinda wish i still had this as philosoma was great for quick gaming sessions, when you only have five or ten minutes to kill. if you're looking for something long term, philosoma is not the answer. It's a nifty diversion for a week or two, but little more.