Rat Attack! is a puzzle / action game developed by Pure Entertainment that was released in 1999 on PlayStation and in 2000 on Nintendo 64. The object of the game is to clear each level of a certain total of rats, without getting hit enough times to lose a life, or ensuring the room wasn’t destroyed, which would also kill you. [Info from Wikipedia]
LavaWave has found some beta Rat Attack screenshot with removed levels , high quality models (instead of the low quality ones in the final game) and a boss stage with the scorpion king totally revamped (probably a target render). Also, the official site of the game surprisingly is still alive since 1998 or so, in which we can read an interesting “the making of rat attack” section.
Thanks a lot to LavaWave for the contribution!