Yes, it's true. Another tower defense game has been released. But it's not just another TD. The Sentinel series is about as iconic and steeped in ios tradition as the tower defense genre itself. Origin8 is back with Sentinel 4: Dark Star [$0.99]. Years have passed since Sentinel 3 [$0.99] and I am happy to see a number of improvements and an increase in depth in the latest iteration. Equipped with a new coat of paint and a fresh wax job, the series has set out to bridge the four year long gap.

If you are new to the Sentinel franchise, welcome to the gold standard of TD ios games. Sentinel as a series has remained true to the TD formula and executes it solidly. Over the years Sentinel has been the mold that other games adhere to or break from. If you are looking to put a typical tower defense game on your mobile device, you are in the right place. The downside of this is that if you are tired of the genre I don't know if you are going to find something refreshing enough to bring you back. The issue as I see it is that even four years ago when the previous game was released, tower defense games were old hat. The majority of recent titles have gone outside the genre to import new life into our trusty towers, but not so with Sentinel.


If you played Sentinel 3, you are going to find the gameplay very similar. Yes there are a few new bells and whistles, but the biggest departures from stock TD that this game has are from Sentinel's past. Previous versions introduced the command mech, which is a semi-mobile mech warrior style fighter that you can position near a wall or the base. Another feature that Sentinel 4 is bringing back is the drone system. Previously you had to decide between beefing up towers or bringing out drones, but they are now bought with the slowly building energy your base builds up which is a nice pacing change. Dark Star combines these features with a deep upgrade path for almost everything you do in game. I don't mean increasing tower levels during a game, I mean there is a separate menu dedicated to permanent upgrades. Each tower, each sentinel skill, each selectable mech, and even wall structures can all be upgraded with the credits you earn in game. Additionally, the ability to salvage wrecked towers has a big impact on gameplay, keeping you in the game even if your towers start to go down. It is a great way to keep gameplay a little more dynamic. There are a few in app purchases, but they are non-intrusive and minimal credit packages, no coin doubler.

Sentinel brings back it's 4 difficulty settings from previous incarnations as well. Each one seems finely tuned. Hard can be a stretch, Medium makes you pay attention, but Psycho really tests your ability to micro manage. It's not going to steal the lime light, but difficulty balance can easily break a game. Origin8 is too seasoned to let anything slip out of place, even with the deeper upgrade system that Sentinel 4 boasts.

One thing missing from this latest release is the classic mode. Campaign has a brief yet contiguous story line that rolls along as you chart a course across the surface of the planet. Endless mode is alive and well, unlocking for each map as you clear it the first time in campaign. The overall interface has been reorganized to give a sleek minimalist journey from the splash screen to getting into the gameplay. I like the effect these changes have. You very fluidly go into the campaign without having to think much about which mode you want to do and endless mode opens up as a result. Some might miss the classic mode, but I think it was a good decision to bring the focus directly on the campaign. It funnels you right into the action without having to choose from multiple modes. A feature that didn't make it but I wish had was the option to view other players' map layouts. It would have been cool to see alternatives or more advanced strategies to help through some of those grueling psycho levels.

There IS a serious amount of refinement that has been built into Sentinel 4. I can't fault origin8 for sticking to their guns in an aging pile of TD games, although I would have really liked to have seen a bigger emphasis on innovation. Staying confined within the genre was probably a conscious design decision. As noble an idea as it sounds, the game feels a bit dated because of it. Some people may have lost their taste for pure tower defense, but for those of us with an appetite there is still meat on this dinosaur's bones.

TouchArcade Rating

  • Wedge598

    I don't know. The graphics and music just don't seem to be keeping up with the times. The 2D sprites were tolerable for the first few games but now it just looks so dated.

    • Jake7905

      The gameplay's the thing, I'd rather play a retro TD game with solid mechanics and progression then a modern grindfest like OTTTD.

      • mrtruffle

        Grindfest? It's hard not to take these insults personally but we have some people saying the game is too easy. The game was designed to be a challenge.

  • FastShoes

    This was an instant buy for me based on their past games. Good on them for charging $4.99 for what they and the reviewer feels is a well put together game. Very glad to hear the IAP is unobtrusive and not necessary.

  • Leguro

    A little disappointed. I will still play through it, but the graphics are a big let down. It almost looks worse than the previous one.

    • Cookies

      I was just thinking that. Not sure how they managed to take a step back in a couple of years...

  • James

    After playing OTTD I don't see a need to run through this one at this point. Good series but don't see a HUGE change from the last one.

    • FastShoes

      I really tried to get into OTTD, but it just felt too much of a grind. Well made though. It seemed like a nice long campaign.

      • mrtruffle

        Check out some of the tutorials online to help get through some levels. Some people had problems because their si NH keep strategy didn't work all the way through. That's because we mixed up the levels so you couldn't spam.

        Sorry for bei MG so defensive but Pat the main designer worked his but off balancing the game every night so we take this feedback seriously

    • Jake7905

      After playing the uneven, but well intentioned, OTTTD, a throwback Sentinel game is exactly what I needed.

      • lll Anubis lll

        Hmmm it said you had -1 likes. I didn't know you could even dislike a post. Ahh well, I liked your post to even you out.

  • diegohostettler

    Pricetag is to high for a basic td like this seems

  • echo_pdx

    Can't recommend. Have to voice agreement with others: it feels dated, clunky, and visually poor. Very disappointing for a long-awaited sequel

  • Jonathan Foster

    Hi guys. I've been playing this game for a few days and I've been really digging it. It has great balance and story but I've stumbled upon a serious game breaking bug. So every turret has a third upgrade level that you have to buy in its tree outside of the game. I bought the one for the laser turret and went to the next level. I leveled it up to max and realized that I could sell it back to the game for 240 dollars. This doesn't make since seeing as the combined total cost of the turret assuming you haven't speced into cost reduction is 160 dollars meaning that you can sell it back for a profit of 80 dollars. What this means is that you can pause the game build a turret, upgrade it to full and sell it over and over for infinite money. I don't think I need to explain how that kind of ruins the game. Anywho figured I'd leave a comment because I don't think it's meant to be this way.


Sentinel 4: Dark Star Reviewed by Andrew Fretz on . Rating: 4