I've just played about an hour of Siege and it's seems pretty decent although there is a real clash of concept.
It comes across as a hardcore tactical shooter but there are inclusions that leave me baffled and make the game seemingly dumbed-down to appeal to everyone. There is no mini-map which is great but then they shoot themselves in the foot by highlighting your team mates with a ghostly glow at all times and there is no friendly fire either. By being able to see your team mates through walls and even on the other side of the map; you can see exactly where they are, where they get shot, how they die and where the enemy is placed. It's such a glaring design issue that renders communication redundant in some instances as you can see everything unfolding with visual aids including likely enemy placement. You also have the ability to reload at any given time and retain all your unused ammo which mimics that of an arcade shooter like COD. You don't need to worry about conserving your ammo or when to reload.
The worst addition by far is the ability to revive your team mates. It only takes a few seconds to get them back on their feet and reminds me of the painful old COD days with Final Stand and Second Chance. This is sheer stupidity from Ubisoft on a ludicrous level and I cannot understand why they think this idea would be welcome or why they've even considered it putting it in the game. The fact a fellow SWAT team member who's a sharpshooter can suddenly perform miracle surgery in a live situation in 3 seconds just beggars belief.
I played on two maps; one was a house and the other way an airplane. Both look like they will be good fun but I am fearful that there isn't much variety in this game. The defenders can barricade windows, doorways and other entrances and the attack team can blow up certain areas to breach but the options after just a few games and the tactical variations just become limited. It's like playing Search and Destroy on Nuketown - there is only so much stuff you can do before you repeat the move over and over. Both teams at the start have a 'prepare' phase which is also limited - the attack team has RC Cars to scope out the premises and 99% of the time; it's exactly the same setup from the defence as the last round and the defenders can do their barricade prep which involves just covering up the same doors and entrances over and over. Just seems so limited.
The alpha is somewhat lacking in visual and animation textures which is expected but it certainly will appear polished on release I'm sure. Characters and weapons can show through walls, doors and equipment and some of the character movements are cringeworthy. The menu interfaces and in-game HUD are also very ugly. The bullet detection is a bit iffy also.
I think this game could be decent but it needs a lot of work and desperately needs a hardcore type mode because what is on offer so far is just so basic and user-friendly; it kind of destroys the game type it's trying to be. If they don't have a dramatic rethink on certain aspects; it could get very boring, very quickly. I'm not really surprised this game has such significant design flaws as Ubisoft are notorious for hideous gameplay execution on many titles but I'm almost mortified at some of the features this game has. There is certainly potential here but the developers need to make sweeping changes/additions before the beta.