Finnaly found the BFT, the bosses seem to be related to the type of upgrades you choose, so if you cant find the one you need, start over and choose a different path...
been playing for about 3 hours now lovely game, great it doesnt have lives etc. Its getting rather hard even with lvl5 guns ( lvl 4a easy mode) .One major complaint though, the weapon switching, I dont know how many times it happened that I accedently picked up a crappy weapon and had to sit it out for 10 mins or more just to get my best weapons back.
Its a pretty lame adventure game, actually you cant even call it that, its a 'find the hidden item' game nice effort but put some more work into your next game 3/5