Whilst not in the same 'vein' as your original post, you could try a look at Killing Floor.
Yes, there's no build up to the shooting so it's very much action-based.
But ramp up the difficulty and it's very much a tactical game, sharing your money between team members, choosing what weapons to upgrade to and when, what classes fit together to make a decent team, not to mention limited buy/sell time at the trader.
Pick it up when it's on a Steam sale and it's usually about £4 or less!