I was reminded of an old game. Out of curiosity I want to check if it was widely known.

I played it in 1995-1997 on the Atari ST. I suspect that it could be taken in the years 90-94. The game consisted of two different models. The first was driving - the view a bit like a Lotus. The main character during shooting at other cars that go ahead and also shelled. It was even more like Chase H.Q but with a little worse graphic and animation. Generally, I think we were some kind of a policeman or detective.

Every few minutes, the racing / shooting drove into some base/den/builiding full of enemies. The view changed in typical 2D platform (but rather with shooting than jumping over the edges). There might be a few floors in that builind, but we could see all of them (or few of them) at one time, like in similar games based on this model.

There was also this characteristic sound of main character, when he jumped he shout someting like "yup". Therefore, with colleagues called this game "yupman" :). From what I associate first base was maintained in beige and gray design. The second in a rotten green.

I forgot about this game and never have heard about it but it was quite fun to play ;)

Techno Cop?
video

(I don't know the game myself, I just did a search on mobygames according to your criteria)

I don't remember a game quite like that one. Sounds like it was inspired by the old arcade game Spyhunter. Could it be a port?

There were no platforming sections in Spy Hunter as far as I recall, only driving and sailing (the car transformed into a boat if you drove it into the water).

Yup, the "yup" is there all right
https://www.youtube.com/watch?v=c1009PEDLCE&feature=player_detailpage#t=66

It's gotta be Technocop, no doubt about that.

I still remember playing that for the Spectrum.

Yes! That's it, thank you!
Was that game popular? :)

I remember playing Technocop on the Genesis and hating it. Maybe it's just me though.