For me, the DFBHD-TS expansion was not as involving as its parent. I enjoyed the original DFBHD, perhaps influenced by knowledge of the backstory of events in Mogadishu garnered from the book and movie. Nevertheless the gameplay and types of missions are similar to those in BHD, so arguably it is more of the same, which is not so bad.
In TS your team goes through a set of "linked" missions with only a minimal backstory garnered from the pre-mission briefing document, reminiscent of Code of Honor. There are two sets of campaigns, each with a handfull of missions, in which your Delta, Ranger or SAS teams take on (1) drug narco-terrorists in the jungles of Colombia and (2) the forces of a renegade Iranian general in the oilfields of Iran. While the backstory is a bit thin, it is superior to that offered in the single player missions of Battlefield 2 for example. Each mission has a number of objectives such as eliminating enemy positions, blowing up installations, securing documents, rescuing hostages and each campaign ends with terminating the well protected enemy leader. You are guided to successive objectives via waypoints on your HUD compass. You can also access a map which is useful for determining the location of power-ups and weapons armories.
The missions are of varying length, difficulty and indeed interest. There are several firefights but alas, like in DFBHD, enemy AI is less than intelligent. If you need to replay a segment of the mission the enemy units will be exactly where they were the first time and react in the same ways. Playing at higher difficulty settings does not result in improved AI, but there seem to be more enemies to fight in each area. Your character seems to take more damage on the Easy setting. Overall I got the impression that the missions in TS were somewhat harder than BHD however there are fewer instances of civilians wandering into the line of fire.
My previous theory, as noted in my DFBHD review, was that the "poor AI" may actually "replicate" the actions of the untrained teenagers and men handed AK-47s by the enemy leader. However the forces of the renegeade Iranian general are meant to include elite units so my thesis becomes less tenable in TS. So, the AI in the game is simply poor, but as noted some missions are very hard. Each mission has a limited number of saves however this does not seem to be related to the difficulty of the mission itself or the gameplay difficulty level you select. For example, the second last mission in Iran may need, say, 3 or 4 saves but you get 7, whereas the finale could do with about 5, but has only 3. This tends to make some missions very frustrating indeed.
Use of binoculars are recommended as firefights can take place at very long range. While enemy assault weapons and rifles seem reasonably inaccurate at long ranges their RPGs seem to have uncanny accuracy. You can change your weapons loadout at armouries that are on most mission maps but you cannot pick up weapons from terminated tangos. The selection of weapons is not as extensive as in say Rainbow Six 3, but you experiment with different primary and secondary weapons for each mission and change at the armoury. Note that the default accessories, such as satchel charges or AT4, are the most suitable for the mission.
There is a limited tactical element to DFBHD-TS and this revolves around commands that can be given to your DF unit. The most useful one is the room takedown command but as the game is primarily outdoors in non-urban areas there is little scope to use this element. Other commands instruct your team to hold fire or lob grenades. Note that friendly AI is little better than the enemy AI ... your character will be doing all the hard work. Sometimes enemy & friendly AI are only several metres apart firing off shots oblivious to each other. Occasionally you will dash for cover from enemy RPGs while your team stands in the middle of the street with the rockets buzzing past.
I see DFBHD, Delta Force Xtreme and the Joint Operations games as genre "rivals" to Battlefield 2. I played the DF/JO games before BF2 and find aspects of the gameplay superior to BF2 but BF2 wins out on realism and attention to detail. Both BF2 and DF/JO are well supported in terms of mods, map and MP servers.
Character graphics are comparable to Rainbow Six 3 era but still stand up well for its vintage, but is far behind that in BF2. Environments are reasonably well rendered and it is unfair to compare to something like COD4 or GRAW as these games install from a CD, not DVD, ROM so there is less room for arguably overdone graphics. The soundtrack and dialogue is unremarkable however the sound effects are quite good.
On the plus side DFBHD/TS will run happily on older PCs and laptops as the graphics requirements are not at all demanding, something that cannot be said for recent FPS games. As with most FPS games a few glitches can arise, for example, your team-mates can stuck running at walls. However apart from this no crashes or hangups occured for me despite running game at maximum graphical settings. What did happen from time to time was that the HUD waypoint compass would not update even though an objective was accomplished. This seems to arise when you don't "land" on the waypoint termination point and can be solved by cycling the waypoints (F7).
TS, like the other DF games I have, is a scripted, or as some say "on the rails", FPS but being largely focussed on outdoor, rather than indoor, engagements, you are reasonably free to flank and roam around. Like BF2 you are warned if you are leaving the mission area. It is important to get "onto" the waypoint termination point for the HUD compass to update especially if you follow a less direct, often safer, route to the waypoint.
My favourite games are the purpose built single player FPS games like the COD or MOH games and the DF games, like BF2, are perhaps better suited to multiplayer. Alas I'm not really interested in playing multiplayer online but will play single player LAN against enemy bots alas one cannot do this with DFBHD or TS, but can with DFX and JO.
OVERALL: TS, like BHD, is not the best FPS game I have played ... but it is far from the worst. Despite some negatives DFBHD and TS are good "vanilla FPS" games that will give at least one enjoyable playthrough. Replayability is somewhat limited due to the scripted nature of the missions but there are "free" mods and maps to try.
Of course being reasonably early and popular FPS games the Delta Force games still have a large loyal following. As a consequence the Delta Force and the related Joint Operations games are, like BF2, supported by numerous fansites which have COOP, SP and MP maps and mods ready to download to enhance your gaming experience (for example: www.novaworld.com/Exchange, www.dfbarracks.com, www.dfreload.com, and www.nova-inside.com).
An outline of the major mods relevant to DFBHD+TS follows. ALL the mods listed below provide additional (new) weapons (eg. throwing knives, Uzi, bomb vests, etc), new or modified multiplayer maps, new skins for your or enemy characters, new character types (eg. SEAL and CIA operatives, terrorists, etc) and all but ADX allow you to replay the original BHD and TS SP missions with these new weapons and skins. Other key features observed from limited (non-MP play) are listed below for each mod:
o Shock n Awe (v4.0) = new weapons, new skins (including tropical cammo in desert, hmm), and changes to original environments.
o Deep Jungle (v.1.6) = new weapons, 6 challenging SP tropical island/jungle missions with very attractive maps and excellent ambient and weapon sound effects. You play as a single DF (Land Warrior based) character, not team. Mission 3, Grave of God, is very different. (Check under my profile for some tropical island holiday snapshots, with Steyr AUG in hand).
o ADX = multiplayer only maps, no SP capability.
o TerraNova (v.2.0) = 1 new SP mission "Operation Orca" with hovercraft insertion and submarine extraction!
o Naval Special Ops (v2.0) = SEAL skins and weapons.
o Black Ops (v1.0) = CIA and black cammo (in desert at daytime, hmm).
o Black Ops Final Conflict (v2.4) = updated BO.
o War of Terror (v1.2, aka Terror Vengeance) = new skins & textures.
o SWAT (v1.0) = 6 urban SP missions in a discontinued MOD.