I liked Bulletproof. It really felt like a PS2 game. There was nothing special about it and it didn't change the game, but it was more fun than Blood in the Sand.
I didn't care for Bulletproof. I remember picking it up for a few dollars after doing a bit of gamer math and noticing I had just enough for a $5 game and tax. Should've saved that money.
That's the main appeal of it. I actually like hunting games like this. Ones that aren't completely awful with mechanics (they aren't anything special) but they blow elsewhere.