The result of those changes is that combat is no longer turn-based. Instead, action takes place in realtime, though you can always pause if you need to plan your next move. At first glance, it may remind you of Frozen Synapse... but a lot simpler.
Besides combat, you'll see a lot that's similar to earlier installments of the saga: a 'realistic' setting that combines a story of revolutions and mercenaries with serious weaponry, tons of enemy soldiers, resource-management, etc.
The game's graphics aren't its strong point, but they don't detract from the experience either. The best part of playing isn't seeing your mercenaries kill their enemies, but rather knowing that they're succeeding thanks to your good decisions.
Jagged Alliance - Back in Action is a sequel that's well worth your time to play. If you liked the other games in the series, you shouldn't miss out on this update.
The demo version only includes one mission.