I just don't get where the 1999 tag comes from. A 150MHz Pentium is an early 1996 processor, and it is not fit to run gamer that were released much later than that. If you set the FSB to 66MHz you can use the processor at 166MHz and this would be the state-of-the-art intel desktop processor in early 1996. Late 90s means P2/P3. This would be a great machine to run games from the 486 era up to 95/96 games.
Of course, you can just plop a cheap MMX 200/233 processor in that motherboard and get it into mid 1997 territory, adding a Voodoo in the mix would also allow games that support Glide to run a lot better. Also, upgrade the memory. Find what is the highest amount of RAM that MoBo will cache and max it out. Windows will thank you. You can push the machine even further with a later AMD processor, but those are better off in a SS7 board.